Donald Trump on Thursday stopped just short of announcing another run for the US presidency in 2024.

He is out campaigning for Republicans ahead of next week's midterm elections.

"This is the year we're going to take back the House," he told a cheering crowd in Sioux City, Iowa.

"We're going to take back the Senate. We're going to take back America and then in 2024, most importantly, we are going to take back our magnificent White House," he said.

"I will very very, very probably do it again," Trump said, "Very, very, very probably."

Biden playing defense

Meanwhile, the current occupant of the White House, President Joe Biden was also making a campaign swing largely focused on shoring up support in Democratic party strongholds.

He argued refusals by Republicans to accept election defeats, starting with Trump's following the 2020 election, risks the nation's democratic survival.

"Democracy is on the ballot," Biden said in Oceanside, California.

"The truth of the matter is that ... this election is going to determine the direction of the country for at least a decade or more."

Biden's four-state, three-day trip also includes New Mexico, Illinois and Pennsylvania, where former President Barack Obama will join him at a rally Saturday.

A president's party typically faces significant losses during midterm elections.

If Republicans seize control of Congress, Biden will likely face a permanent political dogfight and legislative gridlock over the next two years of his administration.