US President Donald Trump has threatened again to declare a national emergency to fund a border wall without Congress's approval, BBC reports.
"I have the absolute right to declare a national emergency," he told reporters.
The White House has denied reports the possibility of diverting funds set aside for reconstruction projects was being explored.
The government has been in partial shutdown for 20 days, leaving about 800,000 federal employees without pay.
President Trump refuses to sign legislation to fund and reopen the government if it does not include $5.7bn (£4.5bn) for a physical barrier along the US-Mexico border.
But budget talks have come to a standstill as Democrats - who control the House of Representatives - refuse to give him the money.
Republican leaders insist the party stands behind the president, although some Republican lawmakers have spoken out in favour of ending the shutdown.