President Donald Trump is trying to make sure House Speaker Nancy Pelosi doesn’t get to visit the troops in Afghanistan, her spokesperson says.

On Thursday, Trump canceled a military aircraft that was scheduled to take Pelosi and a delegation of congressional Democrats to Afghanistan, less than an hour before takeoff, cheekily suggesting Pelosi could “fly commercial.”

“I am sure you would agree that postponing this public relations event is totally appropriate,” Trump wrote about Pelosi’s trip to visit the troops. “Obviously, if you would like to make your journey by flying commercial, that would certainly be your prerogative.”

Now, Drew Hammill, Pelosi’s spokesperson, says the White House even leaked the Democratic delegation’s commercial flight plans, raising the security threat so high that Pelosi and fellow lawmakers had no choice but to postpone their trip.

Hammill said his office learned that multiple administration officials had shared the delegation’s commercial flight plans to the press — though the media outlets didn’t publish the information. The State Department also sent them a memo that the president’s letter had significantly increased danger to the congressional delegation, the troops, and government officials. The White House has not responded to Vox’s requests for comment.

However, one official told reporters, “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.”

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 travelers on the flights. — Drew Hammill (@Drew_Hammill) January 18, 2019

Just as Trump’s trip to Iraq to visit the troops over Christmas — and during the government shutdown — was kept a secret, congressional delegations’ travels to war zones also follow security protocol.

Before Trump’s letter, the details of Pelosi’s trip had not previously been made public, due to security concerns. According to Hammill, the delegation of lawmakers was planning to stop in Brussels to meet with NATO allies and military leaders before going to Afghanistan to meet with the troops. They were planning to return by Tuesday evening.

The backdrop to all of this, of course, is the government shutdown, which is nearing its 28th day. Pelosi had suggested that Trump postpone his State of the Union speech earlier this week until the shutdown was resolved. Trump appeared to suggest Democrats’ Afghanistan trip warranted similar treatment.

The shutdown fight is getting bitter

There has been little progress between Trump and Democrats to end the partial government shutdown, which will hit the month mark over the Martin Luther King Jr. Day weekend. Funding for nine of 15 federal departments expired on December 21, leaving close to 800,000 federal employees without pay.

Instead, Pelosi sent Trump a letter earlier this week recommending they postpone his State of the Union address until the government reopened — or that he send his address to Congress in writing. Then a White House official has said all congressional delegation trips will be canceled or postponed during the shutdown from here on. A trip for senior White House officials and Cabinet members to the Economic Forum in Davos, Switzerland, has also been canceled.

Trump went to Iraq to visit troops over Christmas, when the government was shut down, and New York Republican Rep. Lee Zeldin led a delegation to Kuwait over the same period to visit deployed military members.

The impasse comes over Trump’s demand for $5 billion in border wall funding — a debate Democrats refuse to have until Trump agrees to reopen the government.

House Democrats have repeatedly voted in favor of reopening the government, with the support of a handful of Republican lawmakers. However, Trump and Senate Republicans have been unwilling to make concessions on funding for the border wall.

Correction: this post has been updated to reflect that the administrations’s trip to Davos has been cancelled.