New York: US President Donald Trump has capitulated to his Democratic opponents by agreeing to re-open the US government without securing any money for a wall on the border with Mexico.

Just a day after vowing he would not cave in to demands that he end the government shutdown, Trump announced he would re-open the government for three weeks of negotiations on border security.

Trump warned that unless he secured funding for a wall, he would shut down the government again on February 15 or declare a national emergency to build it without Congress' approval.

As the longest shutdown in US history entered its fifth week on Friday, the Federal Aviation Administration announced it was stopping flights temporarily into New York's LaGuardia Airport because of a lack of staff.