Trump warns of 'very long' govt shutdown without wall funds

US President Donald Trump is ratcheting up the pressure on Congress over a potential partial government shutdown before the Christmas holidays

President Donald Trump on Friday threatened a "very long" government shutdown if opposition Democrats refuse to approve funds for more border security and a wall on the US border with Mexico.

"Shutdown today if Democrats do not vote for Border Security!" Trump fumed, one of a string of tweets on the subject.

"The Democrats, whose votes we need in the Senate, will probably vote against Border Security and the Wall even though they know it is DESPERATELY NEEDED.

"If the Dems vote no, there will be a shutdown that will last for a very long time. People don't want Open Borders and Crime!"

Trump and congressional Democrats remain far apart as a midnight Friday deadline looms to approve funds to keep the US government up and running.

Without an agreement, key agencies will close and many workers will be furloughed right before Christmas without a paycheck.

Trump appeared to harden his demand for $5 billion in funding for the wall on the US-Mexico border, a pet project he has fought for since he began campaigning for president in 2015.

"Even President Ronald Reagan tried for 8 years to build a Border Wall, or Fence, and was unable to do so. Others also have tried. We will get it done, one way or the other!" Trump wrote.

According to Trump, "The Democrats are trying to belittle the concept of a Wall, calling it old fashioned. The fact is there is nothing else's that will work, and that has been true for thousands of years.

"It’s like the wheel, there is nothing better. I know tech better than anyone, & technology..... on a Border is only effective in conjunction with a Wall."