McCarthy said to reporters.
Trump's letter - which was publicly distributed by the White House - came a day after Pelosi wrote him asking for a postponement of his January 29 State of the Union address if the partial government shutdown doesn't end this week.
With the shutdown in its fourth week, that suggests the economy has lost almost a half-percentage point of growth so far, though some of that occurred at the end of last year and some in the first quarter of this year.
In the meantime, the Trump administration continued to try to mitigate the shutdown's impact. But Trump was not expected to sign the national emergency declaration he's been threatening as an option to circumvent Congress, according to two people familiar with the planning.
About two hours after Trump grounded Pelosi and her delegation, an Air Force-modified Boeing 757 took off from Joint Base Andrews outside Washington with the call sign "Executive One Foxtrot", reserved for the first family when the president is not travelling with them.
In a letter to Pelosi denying her delegation the use of a plane, the Republican president called the trip an "excursion".
"I am sorry to inform you that your trip to Brussels, Egypt, and Afghanistan has been postponed", the statement read.
Trump's intervention stopped the trip just as Pelosi and other lawmakers were about to travel. It pointed out that she had invited Trump to make the State of the Union address at the Capitol, but said the shutdown made even the address' location a hard situation.
Meetings to reassure North Atlantic Treaty Organisation leaders in Brussels were also planned in the wake of recent media reports suggesting Trump - well known as one of the group's most prominent detractors - has contemplated pulling the USA out of the military alliance entirely. Trump belittled the trip as a "public relations event" - even though he had just made a similar warzone stop - and said it would be best if Pelosi remained in Washington to negotiate to reopen the government.
Huawei will unveil world's first 5G foldable smartphone next month
For most of 2018, Huawei was third behind Samsung and Apple, but managed to overtake the Cupertino giant in August. Huawei denies that these concerns are valid.
After days of bitter clashes between Trump and House Speaker Nancy Pelosi, it was unclear if the twin developments represented serious steps toward resolving the nasty partisan fight or posturing.
In her letter, Pelosi referenced a dispatch from September from Homeland Security Secretary Kirstjen Nielsen designating the State of the Union address as a "National Special Security Event".
"The bus went around the block and back to the Capitol where members eventually got off", said Fox News' Jason Donner.
It was the latest turn - and potentially the most unsafe - in the high-stakes brinkmanship between Trump and Pelosi that has been playing out against the stalled negotiations over how to end the partial government shutdown. The agency later said it was capable of securing the venue. Republican Sen. Lindsey Graham tweeted: "One sophomoric response does not deserve another".
He criticized Pelosi's move on the State of the Union as "blatantly political" but said, "President Trump denying Speaker Pelosi military travel to visit our troops in Afghanistan, our allies in Egypt and North Atlantic Treaty Organisation is also inappropriate". "I don't know how that could happen".
In a notice to staff, the State Department said it can pay most of its employees beginning Sunday or Monday for their next pay period.
One unnamed senior White House official told Fox News that Trump canceled Pelosi's trip because she wouldn't have returned to the US until Tuesday night, which is when the next federal pay period would occur if the government were open.
Trump and others on-and-off used the term "wall".
Trump was taken by surprise by Pelosi's move to postpone his address and told one adviser it was the sort of disruptive move he would make himself, according to a Republican who is in frequent contact with the White House and was not authorized to speak publicly about private conversations. The measure was voted down 195-222, and the House Democrats will continue with a plan to vote on another appropriations bill next week that will fund the government through February 28. "However, I continue to believe the Senate should pass and the President should sign the bills reopening government that the House already passed".