Members of Congress travelled home for Christmas over the weekend but Trump has stayed on in Washington as a partial government shutdown grinds on, brought on by an impasse between Democrats and Republicans over Trump's proposed border wall.
Mulvaney, who also runs the White House budget office, said he's awaiting a response from Senate Democratic leader Chuck Schumer of NY after the administration on Saturday presented Schumer with a counteroffer in the long-running dispute over funding the wall.
He predicted the shutdown could go into January, when Democrats assume control of the House based on their midterm election gains. The negotiations have centered on border security funding amounts and how that spending would be restricted. He promised to build a wall, and he is going to fight hard to keep that promise.
Days after a GoFundMe was set up to raise money for a wall along the US-Mexico border, a counter fundraiser has popped up.
The Democratic leaders added that Trump is beholden to "right-wing radio and TV hosts" on the issue of the wall, and that "different people from the same White House are saying different things about what the president would accept or not", making it impossible to negotiate.
Clymer says on the page that "We saw some folks are raising money for a border wall to keep out our migrant siblings and fellow human beings, who are fleeing violence and persecution and whose tragically-underpaid labor is essential to the USA economy.
The stock market is tanking and the president is waging a personal war on the Federal Reserve - after he just fired the Secretary of Defense", read a statement from House Minority Leader Nancy Pelosi and her Senate counterpart, Chuck Schumer.
However, the Democrats - and some Republicans - have made clear they will not vote for Trump's cherished border wall.
Trump has stopped talking about a concrete wall in recent weeks and focused on building a more fence-like steel structure.
"The White House is engaged in talks with Senate Democrats, and when the Senate acts, the House will be prepared to follow", Ricci said.
With ultra-conservative lawmakers and media commentators demanding that the president stick to his campaign promises, Trump stood his ground on the wall.
Democrats and some Republicans in Congress oppose the plans as impractical, unnecessary and fuelling xenophobia against Central Americans.
Some other Washington tourist sites including the White House Visitor Centre, National Christmas Tree, and National Archives - home to the US Constitution and other historic documents - were closed.
About three-quarters of the government, including the military, is fully funded through September 2019 but the shutdown forced several other major agencies to cease operations from Saturday.
Hundreds of thousands of federal employees will have to work unpaid or are furloughed, a kind of temporary leave. Absent from the guest list were GOP leaders.
Earlier this week, he said: "This is our only chance that we'll ever have, in my opinion, because of the world and the way it breaks out, to get great border security". The Senate had already passed legislation ensuring that workers will receive back pay, and the House was likely to follow suit. All told, the administration says, he wants 700 miles of wall at a total cost of $18 billion. Democrats say no way and have offered $1.3 billion for what they call border security.