U.S. President Donald Trump has postponed House Speaker Nancy Pelosi's upcoming trip to Brussels and Afghanistan, asking her to stay to negotiate an end to the partial U.S. government shutdown, BBC reported.

The president was able to halt the trip by denying the use of military aircraft to Pelosi and a delegation.

On Wednesday Pelosi had urged Trump to postpone his State of the Union address, amid political deadlock.

Trump's move came on the 27th day of the U.S. longest-ever federal shutdown.

The Republican president wants $5.7bn (£4.4bn) of congressional funding to build a wall on the U.S.-Mexico border, but Democrats have refused.

Trump's cancellation of the trip emerged less than an hour before the Democratic speaker of the House of Representatives was scheduled to leave on Thursday afternoon, U.S. media say.

White House Press Secretary Sarah Sanders shared the president's letter in a tweet.

The president added that Pelosi could proceed with the trip - which he described as a "public relations event" - using a commercial airline.

Later on Thursday the White House announced it would not send a U.S. delegation to the World Economic Forum in Davos, Switzerland later this month, over the shutdown.

"Out of consideration for the 800,000 great American workers not receiving pay and to ensure his team can assist as needed, President Trump has cancelled his delegation's trip to the World Economic Forum in Davos, Switzerland," Sanders said in a statement.

Trump had previously said he would not attend, and on Tuesday announced a scaled-back delegation, which was to be led by Treasury Secretary Steven Mnuchin.

Drew Hammill, Pelosi's deputy chief of staff, said her travel to Afghanistan had required a stop in Brussels to allow pilots to rest, as well as to meet top NATO commanders "to affirm the United States' ironclad commitment" to the alliance.