The vice president emphasized that President Donald Trump would not agree at this time to reopen the border without a comprehensive deal to end the government shutdown.
A short while after Sanders' tweet, Trump said in his own Twitter post that he will address the nation on Tuesday at 9 p.m. EST (0200 GMT Wednesday) to discuss what he called a humanitarian and national security crisis on the southern US border.
Trump is scheduled to address the nation Tuesday about what he called the U.S. -Mexico border crisis, before traveling there Thursday.
Democrats and several immigration advocates have argued the administration's representation of the issue is inaccurate, and accused them of manufacturing a crisis for the political objective of building the border wall, which Trump campaigned for as a presidential candidate in 2016. Their new speaker, Nancy Pelosi, quickly stepped up pressure on Trump and Senate Republicans by pushing legislation that would fund the shuttered parts of the government through September, and allow a month for talks on border security.
Trump has not backed down from his demand for more than $5 billion in funding for the border wall.
Vice President Mike Pence held a meeting with congressional leadership staff on Sunday afternoon, but after the meeting's conclusion, there was little indication they were getting close to a deal to reopen the government.
Trump has said he opposes a piecemeal approach that does not resolve his demand for a wall.
"As long as the legacy media cares more appearing balanced than accurately informing the public", Pfeiffer said, "Trump and the rest of the Republicans who act in bad faith are going to have a structural political advantage".
Trump has offered to build the barrier with steel rather than concrete, billing that as a concession to Democrats' objections to a solid wall. "He's not building a wall anymore, ' that should help us move in the right direction", Mulvaney said.
Russell Vought, OMB's acting director, said tax refunds for Americans will be processed and will be not be considered "non-accepted activities" during the shutdown.
"If he has to give up a concrete wall, replace it with a steel fence.so that Democrats can say, 'See?"
Two congressional sources told CNN ahead of the meeting that aides were expecting to be given the White House's budget justification for about $5.7 billion for the border wall.
Incoming House Armed Services Committee Chairman Adam Smith, D-Wash., said on ABC's "This Week" that the executive power has been used to build military facilities in Iraq and Afghanistan but would likely be "wide open" to a court challenge for a border wall.