WASHINGTON, Jan. 18 -- The White House on Friday barred Congress members from using government planes without prior written approval, a day after delaying Speaker Nancy Pelosi's planned foreign trip amid the standoff over the partial government shutdown.

"Under no circumstances during a government shutdown will any government owned, rented, leased or chartered aircraft support any Congressional delegation, without the express written approval of the White House Chief of Staff," Russell Vought, acting director of the Office of Management and Budget, announced in a memo to department heads.

"Nor will any funds appropriated to the Executive Branch be used for any Congressional delegation travel expenses, without his express written approval," the memo said.

A day earlier, President Donald Trump told Pelosi that her planned seven-day trip to Brussels, Egypt and Afghanistan will be rescheduled when the shutdown is over.

"During this period, it would be better if you were in Washington negotiating with me and joining the Strong Border Security movement to end the Shutdown," the president wrote in a letter to the top House Democrat on Thursday.

In response, Pelosi's office said she had to cancel a commercial trip to Afghanistan because the Trump administration leaked details of it, undermining security for the lawmakers who planned to go.

The shutdown, the longest in the US history, started on Dec. 22 due to a budget standoff in which Trump requested 5.7 billion US dollars for building a wall along the US-Mexico border, but congressional Democrats rejected his demand.