Ashton Carter, the Pentagon's new chief weapons buyer, said on Thursday that he wants to deal with arms manufacturers based on candour, dialogue and the notion that 'we're in this together' even as he pushes to clean up long-standing acquisition headaches. Calling this a 'tremendous moment' for improving the way the Pentagon buys more than $100bn in weapons each year, he cited a convergence of views among President Barack Obama, Defense Secretary Robert Gates and key lawmakers in the Senate and House of Representatives.

"Now's the time to do better," Carter, a Harvard professor sworn in on Monday, told a small group of reporters in an introductory session at the Pentagon. "This is a real opportunity."In our country, we buy our military equipment from private industry," he added. "So they're our partners in equipping our forces."

He termed it 'really important' to develop a good rapport with the Pentagon's top suppliers.

"I'm trying to figure out how to establish that," said Carter, 54, an international security expert and former Defense Department official, adding that he knew 'all these guys'. "And I would like to have a relationship of sort of candour and dialogue and we're in this together," he said. "That's not always possible, obviously."As undersecretary of defense for acquisition, technology and logistics, Carter oversees more than $100bn a year in arms purchases and a $70bn research enterprise.

The acquisition complex that Carter has taken over has been widely faulted for institutional, bureaucratic and contracting failures, including what Carter told his Senate confirmation hearing was 'low-balling' costs and schedule estimates at arms programmes' outset. Carter said what was ringing in his ears was Gates's oft-stated frustration that the Pentagon was not sufficiently on a war footing even though US troops were fighting and dying in Iraq and Afghanistan in post-11 September conflicts. Improving the Pentagon's ability to acquire weapons more rapidly was another of Gates's quests that Carter said he would seek to put in place.

The Pentagon's top six contractors by sales are, in order, Lockheed Martin, Boeing, Northrop Grumman, General Dynamics, BAE Systems and Raytheon.