US President-elect Joe Biden on December 28 said Donald Trump’s appointees at the Pentagon were stalling on the transition and warned that the country faces security risks as a result.

After he and Vice-President-elect Kamala Harris were briefed by their transition teams on national security, Biden said political appointees at the Pentagon as well as the Office of Management and Budget had put up “roadblocks”.

Biden said after the briefing: “Right now, we just aren’t getting all the information that we need from the outgoing administration in key national security area[s] … It is nothing short, in my view, of irresponsibility.”

He said he was seeking a “clear picture” from the outgoing administration on the force posture of US troops around the world.

“We need full visibility into the budget planning underway at the defence department and other agencies in order to avoid any window of confusion or catch-up that our adversaries may try to exploit,” Biden said.

Trump has refused to concede the November 3 election, which Biden won by some seven million votes and by 306-232 in the state-by-state Electoral College. The president has made unsubstantiated claims of widespread fraud.

The Trump administration has drawn concern by shaking up the leadership of the Pentagon since the election including firing defence secretary Mark Esper, who had distanced himself from the president’s use of force against unarmed anti-racism demonstrators earlier this year.

Trump’s new acting defence secretary, Chris Miller, has said that the outgoing administration had agreed with Biden’s people to pause briefings for the holiday season, an assertion that the incoming team called untrue.

Miller released a statement on December 28 saying the Pentagon’s coordination efforts with the transition team “already surpass those of recent administrations with over three weeks to go”.

He added that Department of Defence officials would continue working in a “transparent and collegial manner” to support the transition.

Trump’s last-minute installation of loyalists at the Pentagon comes amid high tensions with Iran, which Trump blamed for a rocket attack on the US embassy in Iraq ahead of the January anniversary of the US killing in Baghdad of a top Iranian general.