Democrats won control of the US House of Representatives in Tuesday's midterm elections, according to projections by the Associated Press. The result handed Hakeem Jeffries a clear path to the Speakership and ended Republicans' unified grip on Washington.

Democrats gained ground in suburban districts in states including New York, California, Pennsylvania and Arizona. The party needed a net gain of only a handful of seats to overturn the narrow Republican majority held by Speaker Mike Johnson.

The outcome followed a historical pattern in which the president's party loses House seats in his first midterm. Democratic strategists had framed the campaign around living costs, tariffs and healthcare.

President Donald Trump had campaigned heavily in the final weekend, urging supporters to protect his agenda. His party struggled to hold swing districts where his approval ratings had slipped, according to exit polling conducted for the major US networks.

Control of the Senate remained less certain as counting continued into the night. Republicans entered the election with a 53-47 majority, giving them a cushion that Democrats struggled to erase. In Ohio, former senator Sherrod Brown was locked in a close contest with Republican incumbent Jon Husted. A YouGov poll published days before the vote had shown Brown ahead by 50 per cent to 48 per cent.

A Democratic House would gain subpoena power and control over spending bills. Party leaders signalled that oversight of the administration would be a priority.

Senior Democrats on the judiciary and oversight committees said they would scrutinise tariff policy, immigration enforcement and the White House's handling of a possible new offensive against Iran. Republican leaders said they would use the Senate and the presidential veto to block Democratic legislation.

The result sets up two years of divided government before the 2028 presidential election. Jeffries told supporters in New York that voters had chosen a check on the president's power.

"The American people have spoken, and they have asked for a Congress that works for them, not for one man," Jeffries said.