United States President Donald Trump on Sunday held firm on his demand for funding from the Congress for a wall along the Mexico border and threatened to declare a national emergency to secure the money, CNN reported. Constructing the border wall was one of Trump’s main electoral agenda in the 2016 presidential elections.

“I may declare a national emergency dependent on what’s going to happen over the next few days,” Trump told reporters as he left the White House for Camp David, where he held meetings with his senior staff members.

The House of Representatives, which is controlled by the Democratic Party, has refused to allocate the $5 billion sought by the Trump administration, resulting in a partial government shutdown that has paralysed the US government for almost three weeks. Last week, the House passed legislative measures to reopen the government. But Trump threatened to veto it and the Republican-controlled Senate also decided not to approve the measures.

Vice President Mike Pence held a meeting with the staff of the congressional leadership on Sunday, but little progress was reported. It is not clear if he has the authority to strike a deal to end the gridlock, The Guardian reported.

Later in the day, Trump seemed to offer a way out of the deadlock, claiming the administration was now planning to build a steel barrier and not concrete. “It is both stronger and less obtrusive,” he added. “Good solution, and made in the USA.”