Donald Trump is directing US Defence Secretary Pete Hegseth to pay military personnel despite the federal government shutdown.

The president said on Saturday that Hegseth must make sure troops do not miss out on their regular paycheque, scheduled for Wednesday. The directive comes as other government employees have already had some pay withheld and others are being laid off.

"I will not allow the Democrats to hold our Military, and the entire Security of our Nation, HOSTAGE, with their dangerous Government Shutdown," Trump posted on his Truth Social platform.

The Republican and Democratic parties blame each other for failing to agree on a spending plan to reopen the government.

Trump's message asks Hegseth to "use all available funds to get our Troops PAID" on 15 October, when military personnel would see their pay withheld for the first time since the shutdown began on 1 October.