US Democratic leader Nancy Pelosi has cancelled plans to visit American troops in Afghanistan due to claims the White House “leaked” her security plan.
The news comes one day after Mr Trump banned the Democratic delegation from using a military aircraft for the trip.
Mrs Pelosi’s spokesman said on Friday that security officials had determined that Mr Trump’s announcement “had significantly increased the danger”.
The row rages on on the 28th day of a US partial government shutdown.
House of Representatives Speaker Pelosi’s spokesman said that after Mr Trump revoked use of a military aircraft “multiple” White House officials then leaked her plan to fly Democratic members of Congress on a commercial airline to Afghanistan.
Drew Hammill said in a statement: “In the middle of the night, the State Department’s Diplomatic Security Service provided an updated threat assessment detailing that the President announcing this sensitive travel had significantly increased the danger to the delegation and to the troops, security, and other officials supporting the trip.”
“In light of the grave threats caused by the President’s action, the delegation has decided to postpone the trip so as not to further endanger our troops and security personnel, or the other travellers on the flights.”
A senior White House official denied the report, telling the BBC: “When the Speaker of the house and about 20 others from Capitol Hill decide to book their own commercial flights to Afghanistan, the world is going to find out.
“The idea we would leak anything that would put the safety and security of any American at risk is an offensive flat out lie.”
On Friday, Mr Trump took to Twitter to further attack Mrs Pelosi over the “seven day excursion” to a warzone.
Mrs Pelosi told reporters that the “the president outing our trip had made the scene on the ground much more dangerous because it’s just a signal to the bad actors that we’re coming”.
“It was very irresponsible on the part of the president,” she said, adding that it would have been her ninth trip there.
What the background?
Around a quarter of the US government has shut down over the Republican president’s refusal to sign any federal budget that does not include $5.7bn (£4.4bn) of congressional funding to build a wall on the US-Mexico border.
Mr Trump’s decision to take away the military jet – just before the Democrats were due to depart Washington – came after Mrs Pelosi wrote her own letter to Mr Trump on Wednesday, asking him to reschedule his annual address to Congress.
She said that due to the shutdown, security for the State of the Union speech on 29 January, a big day of the political calendar, could not be guaranteed.
When asked if this was retaliation for her State of the Union letter, Mrs Pelosi told reporters: “I would hope not. I don’t think the president would be that petty. Do you?”
On Thursday, Acting White House Budget Director Russell T Vought said in a memo that “[u]nder 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”.
The memo came after First Lady Melania Trump used a military aircraft on Thursday to fly to Mar-a-Lago, the president’s Florida retreat.
On Friday, New York Federal Reserve President John Williams warned that the shutdown could cut economic growth by one percentage point.