CIA Director John Ratcliffe says the US administration led by President Donald Trump has not only halted military aid for Ukraine but also stopped sharing intelligence.

As President Donald Trump's administration continues its sweeping overhaul of the federal government, a federal appeals court is temporarily allowing the president to remove the head of a watchdog agency, overturning a lower court’s decision from this weekend.

A former CIA director has accused Donald Trump of “extortion” by stopping the sharing of US intelligence with Ukraine. John Brennan told Times Radio the “absolutely unprecedented” move could have “devastating consequences” for Kyiv.

Intelligence from the US and other allies also helps Ukraine prepare for Russian attacks, and supplied critical information in the war's early days that allowed Ukraine to thwart Russian President Vladimir Putin's hopes for a quick victory.