Warning came on seventh day of shutdown that began after Trump refused to accept legislation unless it contained wall money

Donald Trump threatened on Friday to close the US southern border with Mexico entirely if his demands for money to build a wall there are not met.

The escalating threats came on the seventh day of a partial government shutdown that began when the president refused to accept legislation to fund government agencies unless it also contained money for the wall.

“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,” Trump said on Twitter.

“The United States looses [sic] soooo much money on Trade with Mexico under NAFTA, over 75 Billion Dollars a year (not including Drug Money which would be many times that amount), that I would consider closing the Southern Border a ‘profit making operation,’” Trump said. “Either we build (finish) the Wall or we close the Border.”

Trump has previously claimed that the US is making money from his renegotiated version of the North American Free Trade Agreement (Nafta).

Donald J. Trump (@realDonaldTrump) 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. Hard to believe there was a Congress & President who would approve!

Many government agencies have been shut down for the last week, after their funding expired when Trump declared he would not accept an extension unless it contained $5bn for his border wall.

About 800,000 federal workers have either been placed on leave or required to work without pay.

The shutdown is expected to continue into 2019, after the House and Senate adjourned on Thursday without taking any action to end the impasse.

The White House press secretary, Sarah Sanders, said on Friday the sides were “far apart” since Democrats will not consider funding a border wall.

“They’ve left the table altogether, so of course we’re far apart, because they’re unwilling to actually do something to help protect our borders,” she told CBS.

Facebook Twitter Pinterest Men sit next to a sign reading ‘mural of brotherhoood’ look at the US-Mexico border fence from Playas de Tijuana in Baja California. Photograph: Guillermo Arias/AFP/Getty Images

In January, Democrats will take control of the House. The incoming speaker, Nancy Pelosi, has said the chamber “will vote swiftly to reopen government and show that Democrats will govern responsibly in stark contrast to this chaotic White House”.

Mick Mulvaney, the incoming acting White House chief of staff, said the White House had offered to accept some amount less than $5bn for the wall, though he would not say what number they proposed.

“The Democrats have simply shut down the discussions. They did not even counter us,” he said Friday on Fox News.

Mulvaney said he believed that the Senate Democratic leader, Chuck Schumer, was “really interested in doing a deal and coming to some sort of compromise”, but Pelosi was “preventing that from happening”.

The longer the shutdown continues, the more the public will feel its effects. Smithsonian museums have so far remained open with money they had on hand, but announced on Thursday that all museums and the National Zoo will be closed starting on 2 January.

Play Video 0:59 Potential border closure is only way to get Democrats' attention, says White House – video

Nine cabinet-level departments, including homeland security and the justice department, are affected by the shutdown, along with dozens of other agencies.

Federal workers are still set to receive paychecks beginning on Friday, which were processed before the shutdown. But those who were supposed to work last Saturday, the first day of the shutdown will be short a day’s pay. The next paycheck will not come if the shutdown continues.

The government offered tips for federal workers unable to pay rent, mortgages or other debt and looking to fend off creditors. “I am a federal employee who has recently been furloughed due to a lack of funding of my agency,” said one of the sample letters from the Office of Personnel Management. “Because of this, my income has been severely cut and I am unable to pay the entire cost of my rent, along with my other expenses.”

Trump has threatened to close the border with Mexico before, as a caravan of Central American migrants were making their way toward the US. That did not happen, though officials temporarily closed the busiest port of entry into the US last month amid clashes with members of the migrant caravan.

Trump 'accidentally reveals location and identities of US Navy Seals in Iraq' Read more

It is not clear how an outright closure of the border would work. At just the San Ysidro port of entry, about 70,000 cars and 20,000 pedestrians cross each day.

Sign up for the new US morning briefing

Trump on Friday also repeated his threats to cut off all aid to Guatemala, El Salvador and Honduras, the countries of origin for many migrants attempting to cross the US border and seek asylum. He said the three nations have been “taking advantage of U.S. for years!”

Meanwhile, Trump is also defending himself from criticism that he was inappropriately political during his visit to US troops in Iraq, where he signed Make America Great Again campaign hats and a Trump 2020 patch presented to him by service members.

“CNN & others within the Fake News Universe were going wild about my signing MAGA hats for our military in Iraq and Germany,” Trump said on Twitter on Thursday evening. “If these brave young people ask me to sign their hat, I will sign. Can you imagine my saying NO?”

He said his team did not bring or distribute the hats.