US President Donald Trump says he will make a “major announcement” later on his Mexican border wall, an issue that has partially shut down government.

The shutdown, now in its fifth week, is the longest in US history and has left 800,000 federal workers unpaid.

Trump insists on $5.7bn  funding for the wall but opposition Democrats refuse to support it.

Correspondents say Trump may offer a concession on so-called Dreamers, who entered the US illegally when young.

Trump insists the wall is needed to end a security crisis on the southern border, while the Democrats call it a waste of taxpayers’ money.