Republican John Kennedy wins Louisiana

Louisiana voters have chosen to send Republican state Treasurer John Kennedy to the US Senate, filling the nation's last Senate seat and giving the GOP a 52-48 edge in the chamber when the new term begins in January.

Kennedy had always been the runoff election's front-runner in a state that overwhelmingly supported Donald Trump. He defeated Democrat Foster Campbell, a state utility regulator whose chances were seen as such a long-shot that national Democratic organisations offered little assistance to Campbell's campaign.

Voters also were filling two open US House seats on Saturday, for the 3rd District representing southwest and south central Louisiana and the 4th District covering northwest Louisiana.

Louisiana has an open primary system in which all candidates run against each other. In the contests for the open congressional seats, the November primary ballots were packed with contenders, so the top two vote-getters advanced to Saturday's runoff.

The Senate runoff drew national attention, with President-elect Donald Trump and Vice President-elect Mike Pence each travelling to Louisiana to rally for Kennedy.