President Donald Trump will visit the US-Mexico border on Thursday, the White House's latest attempt to call attention to what it is calling a "crisis" on the southern border.

The announcement of the trip comes as the government shutdown begins its third week, with Trump and congressional Democrats at an impasse over Trump's demand for nearly $6 billion in federal funding to build a wall on the southern border.

During the trip, Trump will "meet with those on the front lines of the national security and humanitarian crisis," White House press secretary Sarah Sanders announced Monday morning on Twitter.

House Speaker Nancy Pelosi has flatly rejected providing any funding for a border wall to resolve the stalemate. And Trump has threatened to drag on the shutdown for months or even years if he does not get funding for the border wall.

As the shutdown continues, more Americans are beginning to see its effects. Hundreds of thousands of federal workers are furloughed or working without pay. Transportation Security Administration officers at major airports around the country are not showing up for work. Conditions at national parks are deteriorating and the Department of Housing and Urban Development is running out of money for a key housing program.

But for now, both sides are sticking to their positions and negotiations over the weekend between Vice President Mike Pence and Democratic congressional staffers yielded little progress.

Trump administration officials have pointed to a surge in migrant families crossing the border to make their case that the situation at the southern border is reaching critical proportions.

But Trump and his top officials have also pointed to misleading statistics to suggest terrorists are attempting to enter the United States through the southern border. Sanders, for example, falsely claimed on Sunday that "nearly 4,000 known or suspected terrorists come into our country illegally," even though the overwhelming majority of those individuals are blocked from entering the US at airports.