Barack Obama’s grand plan of using US marine exercises in the Northern Territory as a basis for a new military “pivot in Asia” has been finalised and locked in ahead of the Presidential elections next month.

Australia’s role in providing seasonal training base for 2,500 Marines — the original plan agreed to by President Obama and Julia Gillard in 2011 — was under threat from a dispute over cost sharing for facilities in the Northern Territory.

The dispute about shared costs was limiting the original plan to half the annual intake of 2,500 marines and undermining the effectiveness of the joint training scheme.

The end of Mr Obama’s Presidency, Donald Trump’s strident isolationism and threats from the new Philippines’ President Rodrgio Durtete to end US Marine exercises after this year and “break off” with the United States made finalisation of the original plan urgent.

Julie Bishop and Marise Payne were trying to organise an urgent meeting of US and Australian Foreign and Defence Ministers — Ausmin — in Sydney this month with US Secretary of State, John Kerry, and Defence Secretary, Ash Carter, to seal the deal before the election.

Malcolm Turnbull said on his trip to Washington DC two weeks ago, after meeting Mr Carter, that agreement would be reached but left the detail to the Defence Minister and Australian Defence Secretary, Dennis Richardson.

Senator Payne has been in Washington this week meeting Mr Carter and senior US Defence officials to discuss “the bilateral defence relationship and regional security and stability”.

Christopher Pyne, Defence Industry Minister, has also been in Washington this week in discussions over defence purchases and agreements.

A formal announcement of the final agreement is expected soon outside the auspices of an Ausmin meeting.

The US is facing increased pressure in South East Asia to withdraw troops from the Asia-Pacific realm and Australia’s role as the effective host to a battalion of US marines, who could be readily deployed to crises in the region, was even more crucial.

There were also fears that should Mr Trump become President, or even Hillary Clinton, a new administration would baulk at the costs and refuse to finalise the agreement stalling it at half its original strength and even going backwards.

Such a step would be a major strategic reversal in the region and deprive Australia of the opportunity to be a regional base for US military preparedness as well as cutting off millions of dollars from the Northern Territory economy.

As this stage the US Marine commitment for this year, the fifth rotation of US troops since the agreement began, of 1,250 troops is still only half the target President Obama and Ms Gillard envisaged in 2011.

The Abbott Government ratified the first stage of the agreement in 2014 and there were a scheduled 2,500 US Marines expected to be exercising near Darwin by 2016-17.

But because of an argument over cost sharing the troop rotation has stalled at half the target level. The fifth rotation of US marines for six months’ combined training with Australian and other forces in April this year was 1,250, half the final target after four previous rotations of less than half.

The Foreign Minister was confident an agreement would be reached in time soon after a series of meetings she had in Washington DC two weeks ago.

A formal national analysis of the “Force Posture” agreement found failure to implement it would “undermine Australia’s longstanding alliance with the US” — a view endorsed by the Parliamentary Treaties committee last year.

Although the training rotations at the Roberston Barracks in Darwin, which also involve aircraft and pre-positioned military hardware for a rapid deployment force, have begun the fight over the cost of deploying the Marines stalled the increase in numbers.

In April this year the fifth rotation began at Darwin Airport with the arrival of a US Galaxy C5 aircraft carrying CH-53E Super Stallion helicopters from Hawaii and the first of this year’s 1,250 US Marines.

US defence officials described the rotation as “part of the US rebalance to the Asia-Pacific region” and said it was not known when the target of 2,500 troops would be reached.

The officials said it was “not immediately clear when all 2,500 Marines are expected to rotate through Darwin” and that the decisions are made based on a number of variables including cost.

Mr Turnbull said on his arrival in New York for the UN General assembly the negotiations on cost-sharing for the rotation of up to 2,500 marines a year through Darwin was an ongoing negotiation. “I expect them to be resolved,” he said. “These are negotiations that are going on between officials.”

Anti-U.S. base demonstrators and riot police clashed here on July 22, when authorities started removing a barricade set up to obstruct a project to build helipads for the U.S. military.

The Defense Ministry’s Okinawa Defense Bureau, which oversees the helipad project, said the barricade, consisting mainly of vehicles, had been dismantled and that construction has resumed.

But the scuffles involved showed that the protesters are far from ending their opposition to the project.

About 100 riot police arrived at a path leading to helipad construction sites near the Takae district of Higashi village in the prefecture’s northern region around 5:30 a.m.

About 200 residents, conservationists and activists had already assembled there to keep the barricade intact. Some lied down or sat on the path to block the police.

However, the riot police forcibly removed the demonstrators. Shoving matches ensued and screams of anger were heard when the protesters were carried away from the site.

“Are you going to lend a hand in the destruction of Yanbaru?” one of the protesters shouted, referring to the forest where helipads will be installed.

“We are against the helipad for Osprey,” screamed another, referring to the tilt-rotor aircraft used by the U.S. military.

One woman complained of being ill and requested help from emergency workers.

As of 11 a.m., the vehicle barricade had been removed, but more than 100 cars were still parked on the sides of the road to hinder the project. Supply vehicles still cannot enter the construction sites.

Construction started in 2007, and two helipads were completed by 2014. But work to build the four other helipads was suspended after opponents blockaded the path. On July 11, the day after Upper House election, the defense bureau started preparations to resume the project.

POTENTIALLY thousands of extra American sailors and Marines will flood through the Darwin port in coming years with a US General confirming a greater military presence in the South Pacific.

The head of US Marine Corps Force Command, Lieutenant General John Wissler, said the Pentagon planned to dispatch another three-ship amphibious ready group to the Asia-Pacific region as early as October 2018.

The Marine Corps Times reported that the ships would likely carry an embarked Marine Expeditionary Unit (MEU).

That would see an extra 4000 sailors and Marines in the region.

Lt-Gen Wissler said the goal of the MEU was to augment the number of Marines already coming to the Top End as part of the annual six-month Marine Rotational Force Darwin deployment.

This year, about 1250 Marine are deployed to Darwin, based mostly at Robertson Barracks about 20km from the Darwin CBD.

US and Australian officials hope to boost that number to 2500 by 2020.

“The actual basing (of the extra Marines and sailors) ... and all of those significant details are being worked out,” Lt-Gen Wissler said.

“That’s why it’s a (fiscal) 2019 problem because, as you can imagine, it’s a very complex undertaking.”

The Japan-based 31st Marine Expeditionary Unit presently conducts two 90-day patrols in the Pacific each year — one in spring and another in autumn — and respond to humanitarian crises in the region throughout the year.

Lt-Gen Wissler said the new arrangement would allow that unit to focus on north eastern Asia while the new ARG/MEU conducted two 90-day patrols in the South Pacific.

He said the Marine Corps has not determined whether the new MEU will come from the continental US, Hawaii or Japan.

Lieutenant Commander Matt Knight from the US Pacific Fleet said it is too soon to say which ships may be assigned to the MEU in fiscal 2019.

Former Chief of Naval Operations Admiral Jon Greenert said the amphibious assault ship America was a “prime candidate” to visit Australia as part of such a group.

“They will go into Darwin … and conduct on-load and off-load,” he told Navy Times in March 2015.

He said while the Marines trained in the Top End of Australia, the ships in the ARG could operate and hold exercises in South East Asia.

In Japan, tens of thousands of people gathered on the island of Okinawa to demand the ouster of U.S. military bases.

Activists said 65,000 people attended what they called the largest protest in two decades against the U.S. military presence.

The protests erupted after a former marine working as a civilian contractor at a U.S. base was accused of raping and murdering a 20-year-old woman.

The victim’s father has called for the removal of all U.S. bases on Okinawa, which hosts about 26,000 U.S. troops.

At Sunday’s rally, Lia Camargo said U.S. soldiers should also be held accountable for their crimes.

Lia Camargo: "The slogans are like 'get the bases out of here,' but I don’t think it’s that simple. I think making sure that the responsibility of the soldiers, if they do commit a crime, that has to be weighed in the same gravity as a Japanese person who commits that same crime."

The U.S. and Australia have pushed back plans for the deployment of a 2,500-strong Marine Air Ground Task Force to Australia's Northern Territory until 2020 as they nail down the final details, including cost-sharing, Australian officials say.

The Marine Corps started building its presence in the port of Darwin in 2012 and grew its rotational force, which spends six months of the year training there, to just under 1,200 troops by 2014.

However, the growth of the force, which was to have included the task force within five years, has stalled with U.S. and Australian officials reporting only 1,250 Marines there this summer.

Australian Defence Force officials said in an email that they would work toward rotations of 2,500 Marines and equipment to Darwin by around 2020.

Australian national security consultant Ross Babbage said the two countries have been negotiating for three years over who would pay costs associated with the rotational force.

"There is no space on RAAF Darwin and Robertson Barracks (the facilities where Marines stay in Darwin) to facilitate that kind of growth (up to 2,500 Marines)"