Washington (AFP) - US President Donald Trump raised the specter of violence around upcoming midterms Wednesday, saying he did not want to see "unnecessary" unrest days after he reportedly warned evangelical leaders of violent change if Republicans lose control of Congress.

When asked by a reporter why he had on Monday suggested there would be violence around the November elections, Trump simply said "because that's the way."

"If you look at what happens ... there's a lot of unnecessary violence all over the world, but also in this country, and I don't want to see it," he said.

At a meeting with evangelical leaders at the White House, Trump had said everything was at stake for his conservative agenda if his party loses, according to an audiotape of the meeting obtained by the Times.

Democrats "will overturn everything that we've done and they'll do it quickly and violently," Trump reportedly said.

"They will end everything immediately."

"When you look at Antifa," he added, referring to militant leftist anti-fascism groups, "and you look at some of these groups, these are violent people."

Monday did not mark the first time Trump has warned of violence if things did not go his way.

During the 2016 presidential campaign, he said his supporters would probably react violently if he did not win the Republican nomination.

"I think you'd have riots," Trump warned.

The Times said reporters were allowed to listen in on brief comments by Trump during the Monday meeting with ministers and pastors, and heard him talk about abortion, religious freedom and youth unemployment.

But after the press was shown out of the room, Trump changed the subject and suggested how the evangelical leaders could help Republicans win in November, the Times reported.

"I just ask you to go out and make sure all of your people vote," Trump said.

"Because if they don't -- it's Nov. 6 -- if they don't vote we're going to have a miserable two years and we're going to have, frankly, a very hard period of time because then it just gets to be one election -- you're one election away from losing everything you've got."