Washington, Jan 26 (IANS): President Donald Trump has said he is open to a path to citizenship for hundreds of thousands of undocumented immigrants known as "Dreamers" if Congress agrees to fund his proposed wall on the Mexican border.

In exchange for creating a path to citizenship for the young undocumented migrants brought to the US as children, Trump wants Congress to approve $30 billion in funding for border security, including $25 billion for building a wall along the US-Mexico border.

Trump told reporters at the White House on Wednesday that if lawmakers in Congress cannot reach an agreement for the 800,000 Dreamers, he could extend the deadline for ending the Deferred Action for Childhood Arrivals (DACA) programme protecting them from deportation beyond March 5.

Trump said he would allow "Dreamers" to "morph into" citizens over a period of time, the New York Times reported.

"It's going to happen -- over a period of 10 to 12 years. If somebody's done a great job and worked hard," the President said before departing for the World Economic Forum in Davos.

However, the President tweeted that "if there is no Wall, there is no DACA". He told reporters that the wall could be less than the $25 billion he was requesting since it would run for some 800 miles along the border, rather than along the entire 1,989-mile frontier.

Trump issued the Twitter warning about the wall one day after Senate Minority Leader Chuck Schumer withdrew his offer to provide funds for building the barrier.

Democrats are demanding that Republicans approve an immigration agreement that would provide a path to citizenship for the Dreamers, but the President is demanding that in exchange for that funds be allocated to build the border wall.

In September, Trump ended the Obama-era's DACA programme, saying it was an illegal assertion of executive authority by his predecessor.

But even as the President's actions threatened young immigrants with deportation, he has urged Congress to find a permanent solution that could allow them to live and work in the country legally.

Trump campaigned for the presidency with nativist rhetoric that assailed the threat from outsiders, especially Mexicans and Muslims.

As President, he quickly tried to impose a travel ban on predominantly Muslim countries and gave immigration agents more authority to round up undocumented immigrants.

Despite the President's pledge to the "Dreamers", his administration cracked down on Wednesday on so-called sanctuary cities.

The Justice Department asked the asked 23 jurisdictions across the country to furnish documents proving that they had not kept information from federal immigration authorities.