WASHINGTON (AFP) - President Donald Trump on Thursday (Jan 17) cancelled the United States delegation's trip to the annual international conference at Davos, saying the officials were needed in Washington to tackle the shutdown of the federal government.

"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," said a statement from Press Secretary Sarah Sanders.

Treasury Secretary Steve Mnuchin had been due to head the five-strong delegation that also included Secretary of State Mike Pompeo, Secretary of Commerce Wilbur Ross, US trade representative Robert Lighthizer and assistant to the president Chris Liddell.

The decision to scrap the Davos trip came after Mr Trump hit his chief Democratic opponent Nancy Pelosi with a last-minute cancellation of her plan to take an airforce plane to Afghanistan, citing the four-week-old shutdown as a motive.

Some 800,000 federal employees and many more government contractors are affected by the partial shutdown, triggered by Mr Trump's refusal to sign off on funding for a host of departments.

This was in retaliation for the refusal of Democrats, who control the lower house of Congress, to approve his plans for a US-Mexico border wall.

Mr Trump last week cancelled his own participation in Davos, also citing the row over his proposed wall.