ABCNews.com(WASHINGTON) — In the increasingly personal political standoff between President Donald Trump and House Speaker Nancy Pelosi, the president on Thursday said he was canceling her trip to Belgium, and Afghanistan in apparent retaliation for Pelosi asking Trump to delay his State of the Union Address until after the government shutdown ends.

“Due to the Shutdown, I am sorry to inform you that your trip to Brussels, Egypt, and Afghanistan has been postponed,” Trump wrote in a snarky letter released Thursday afternoon. “We will reschedule this seven-day excursion when the Shutdown is over.”

White House Press Secretary Sarah Sanders tweeted out the letter.

A Pelosi spokesman did not immediately respond to a request for comment and it was unclear what travel plans, if any, she had.

Trump added that he feels “it would be better” if Pelosi was in Washington negotiating with him “and joining the Strong Border Security movement to end the shutdown.”

“Obviously, if you would like to make your journey by flying commercial, that would certainly be your prerogative,” Trump noted. “I look forward to seeing you soon and even more forward to watching our open and dangerous Southern Border finally receive the attention, funding and security it so desperately deserves.”

An administration official said that the Defense Department was made aware prior to the letter being sent to Pelosi, and that the policy applies to all CODELs — or congressional delegation trips — that may have been scheduled during the shutdown.

Sanders, when asked why Trump sent the letter to Pelosi, said, “We want to keep her in Washington. If she leaves she guarantees that the second round of paychecks to workers won’t go out.”

She said Pelosi and Senate Minority Leader Chuck Schumer “always have an invitation” to the White House if they want to come to negotiate.

Asked if there is any White House response to Pelosi’s letter to Trump on Wednesday calling for a delay in his State of the Union Address, she said, “We’ll keep you posted. Nothings changed on that front.”

Earlier Thursday, with the shutdown in its 27th day, Pelosi said she had not received a response to her letter, which urged Trump to delay the annual address until after government is reopened. When asked what she’d do if Trump were to insist on sticking to the Jan. 29 date, Pelosi she’d “cross that bridge when we come to it.”

“We haven’t heard. Very silent more than 24 hours,” Pelosi said, seemingly amused. “Have you heard? We haven’t heard.”

At the Pentagon Thursday morning, Trump continued to push for border security, including his proposed border wall, accusing Pelosi of refusing to let Democrats negotiate.

“The federal government remains shut down because congressional Democrats refuse to approve border security,” Trump said. “We’re going to have border security.”

Pelosi and Trump haven’t spoken to each other since Trump walked out of a Jan. 9 meeting with congressional leaders in the Situation Room, declaring it “a total waste of time.”

Last year, Trump delivered the State of the Union to a televised audience of 45.6 million people, leaving the impression that Pelosi is denying the president a prime platform to share his point of view as leverage against the president.

“Let’s get a date when government is open. Let’s pay the employees,” Pelosi said. “He thinks it is okay not to pay people who do work. I don’t. My caucus doesn’t either.”

Pelosi said she is confident security professionals could keep the event safe, but added her qualm is that they would not be immediately paid for their work.

“This is directly related to our security,” Pelosi said, recounting several votes the House has taken to end the shutdown.

Pelosi predicted there’s “bipartisan agreement” to use other technology to protect the border, but stressed “I’m not for a wall,” when she was asked why she hasn’t proposed an alternative dollar figure to counter the president’s $5.7 billion demand for a barrier.

“The president says the only way to do it is with a wall. That’s a debate that we have,” Pelosi said. “We must respect our workers protect our borders and reopen government the government immediately.”

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