U.S. President Donald Trump held a rally Monday in Houston for Republican Sen. Ted Cruz who is seeking to retain his seat in the Nov. 6 midterm elections.

"I'm on his side and I am 100 percent," Trump said of Cruz, his one-time rival for the 2016 GOP presidential nomination who faces a strong challenge from Democratic Rep. Beto O'Rourke.

"Ted and I get along very well, very late into the campaign. And I said don't worry about it, it's only a question of time," Trump told reporters in Washington before heading to Texas.

(Trump speaks to the media before departing for Texas)[Getty/Kyodo]

"And then it became very nasty, and then it was over, and when it was over we've gotten along great."

Trump cited his cooperation with Cruz in promoting issues such as tax cuts and deregulation.

With Election Day only two weeks away, opinion polls and political analysts suggest the Democratic Party is likely to win back a majority in the House of Representatives, but it will be difficult for Democrats to retake both the House and Senate.

All of the 435 seats in the House and 35 of the 100 seats in the Senate are up for grabs in what will be the first referendum on Trump's two years in office.