The back and forth between President Trump and House Speaker Nancy Pelosi, D-Calif., over the partial government shutdown escalated Friday, as Pelosi's office charged the White House leaked plans for a congressional delegation to fly commercially to Afghanistan.

On Thursday, Trump said he was revoking a military flight for the CODEL, suggesting Pelosi fly commercial instead.

Pelosi was apparently prepared to do just that. But in a statement released by her office Friday morning, spokesman Drew Hammill said:

"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," continued Hammill.  "This morning, we learned that the Administration had leaked the commercial travel plans as well."

The White House in a statement released on background, called the charge "a flat out lie."

"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 a flat out lie."

Hammill said that "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."

After releasing the statement Hammill added about the charge of leaking, "this morning, we learned that the Administration had leaked the commercial travel plans as well."

He also responded to the administration saying it was a lie on Twitter.

As speaker, Pelosi is the second in line to succeed the president, and travels with a security team and usually on planes provided by the military.

Pelosi's delegation had planned to visit U.S. troops in Afghanistan. She has made several previous trips there. The original plans also included a stop to meet with NATO leaders in Brussels.

Trump Thursday sent a letter to Pelosi calling the trip "a public relations event," and said it should wait until the government shutdown, now in its 28th day, ends.

Trump's letter came a day after Pelosi wrote to Trump, suggesting he postpone his planned State of the Union address to Congress January 29th because of the shutdown.

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