Trump slams Fox host as 'dumb as rock', US midterm voting wraps

President Donald Trump lashed out at conservative channel Fox News on Tuesday in a sign of early frustration as he watched the US midterm election results at the White House.

The 80-year-old posted three angry messages on his Truth Social network about Fox, blaming its recent ratings decline on not being sufficiently loyal to him.

In one post sent as the first polls closed, Trump said Fox was "way down, not because of me, but because they are AGAINST me!"

In another post Trump blasted one host as "DUMB AS A ROCK", and in a third he slammed a Fox poll of voters opinions as "always the worst."

"FoxNews Ratings are way down (27%!) because they're spending too much time covering the Trump Deranged Dumocrats!" Trump added.

The midterm elections will determine whether Republicans keep control of Congress and will shape the rest of Trump's second term.

His rageposting came shortly before he hosted an "election night viewing reception" for cabinet members and administration officials in the East Room of the White House.

A White House official had earlier described the mood there as "cautiously optimistic."

"The president has left it all out on the field and he's done everything that was needed. Republicans are in a better spot now than they were four weeks ago," the official told AFP.

Trump held near-daily rallies in the month before the midterms, urging Republicans to "pretend I'm on the ballot" despite his own record-low approval ratings.

But polls show Democrats with a good chance of seizing the House and possibly the Senate amid voter anger on the economy and the US war on Iran.

Trump threatened in a telephone interview with the CBS network on Tuesday to be "Mr Veto" and block any Democratic legislation if they win.