Donald Trump's frustration at the denial of his request for $5bn in funding from Congress for his promised wall on the US-Mexico border is building as the government shutdown continues with no end in sight.
The president has once again threatened to close America's southern border unless he receives the funding, and has also threatened to cut US funding to Honduras, Guatemala and El Salvador over what the president claims is a lack of action over immigration.
People from the three nations formed the bulk of the caravans that have reached the US border in recent weeks, with Mr Trump claiming - without evidence - another is forming in Honduras. It comes as US immigration officials face questions over the deaths of two Guatemalan children at the border in the last two weeks.
To see the latest updates, please follow our liveblog.
Democrats have refused to give in to the demand, and it is one of the major factors why a spending bill to keep the government open was not passed before Christmas.
That partial shutdown will now last into the new year.
With large parts of the federal government shut down for lack of funding in a dispute over the proposed wall and Congress adjourned until next week, Mr Trump is in the White House firing off angry tweets.
"We will be forced to close the Southern Border entirely if the Obstructionist Democrats do not give us the money to finish the Wall & also change the ridiculous immigration laws that our Country is saddled with," Mr Trump said.
"Either we build (finish) the Wall or we close the Border," he added.
The Republican president has also reiterated threats to cut off all US aid to Honduras, Guatemala and El Salvador, which he said were not doing anything to stop the flow of migrants toward the United States.
Ms Sanders said of Democrats: "They've left the table altogether, so of course we are far apart."
Incoming acting White House chief of staff Mick Mulvaney has complained that Democrats were ignoring an offer from the White House to agree to lower funding levels to build the wall. Mr Mulvaney said the offer was made on Saturday but Democrats are no longer considering that option.
He said: "There's not a single Democrat talking to the President of the United States about this deal."
He added of the shutdown: "We do expect this to go on for a while."
As Mr Trump baselessly speaks about a new migrant caravan, some of those involved in the trekking to the US border this year have been speaking to Reuters:
Since setting out from Honduras in the hope of reaching the United States, Nicolas Alonso Sanchez has worn a simple wooden cross around his neck â a quiet reminder of the Roman Catholic faith that propels him forward.
"God gave me the strength to get all the way here," Sanchez, 47, says at a temporary shelter where he is staying in the Mexican border city of Tijuana.
On the long journey from Central America to U.S. soil, many migrants have taken solace in their religion.
Several 'caravans' of mostly Honduran migrants who made the trek this year faced arduous conditions, braving fierce heat by day and searching for a safe place to sleep at night.
Mr Trump also claimed over Christmas that he had awarded 115 miles of new border wall construction in Texas. But that appears to confuse work that’s already funded and underway.
Mr Trump tweeted on Monday, “I am in the Oval Office & just gave out a 115 mile long contract for another large section of the Wall in Texas.”
Also, Mr Trump cannot award construction contracts. US Customs and Border Protection and the US Army Corps of Engineers award contracts for border wall construction after Congress approves funding and months have gone into planning.
According to a Reuters/Ipsos poll released on Thursday, 47 per cent of Americans hold Mr Trump responsible, while 33 per cent blame Democrats in Congress.
DHS spokeswoman Katie Waldman said Ms Nielsen is heading to El Paso on Friday. Ms Waldman said Ms Nielsen will tour multiple stations and substations operated by US Customs and Border Protection (CBP).
Ms Nielsen is also scheduled to meet with emergency medical technicians and medical professionals, as well as local officials.
The trip comes four days after the death of 8-year-old Felipe Gomez Alonzo. Felipe was the second Guatemalan child to die in CBP's custody in just more than two weeks.
Ms Nielsen has called the death "deeply concerning and heartbreaking" and requested medical help from other government agencies.
Meanwhile, when asked about Mr Trump's border-closing threat, Mexican President Andres Manuel Lopez Obrador told reporters it was an internal US government matter.
"We take great care of the relationship with the government of the United States," Mr Lopez Obrador said.
"Of course we will always defend our sovereignty ... We will always protect migrants, defend their human rights," he added.
Museums and galleries in Washington DC will begin closing next week if the partial shutdown of the federal government drags on.
The attractions have stayed open by using unspent funds but they are about to run out of money.
Museums and galleries under the Smithsonian Institution umbrella will close from 2 January.
That includes the National Zoo, as well as the National Air and Space Museum, the National Museum of African American History and Culture, the National Museum of Natural History, and several galleries, including the National Portrait Gallery.
"We're here, and they know where to find us," Mick Mulvaney, the acting White House chief of staff, said in an interview with Fox News Channel. "Where is Chuck Schumer? Where is Nancy Pelosi? They're not even talking right now," he said. Schumer is the top Democrat in the Senate and Pelosi is the incoming speaker of the House of Representatives.
A spokesman for Mr Schumer said the White House has been told that there are three existing federal funding proposals containing funds for border security that could pass both the House and the Senate - and that Mr Trump should accept one of those.
Please allow a moment for the liveblog to load.
