US President Joe Biden’s Democrats have inched closer to keeping control of the Senate, with a projected win in Arizona following the midterm elections.

Three days after Americans voted, the BBC’s US partner CBS estimates Democrat Mark Kelly has beaten Republican challenger Blake Masters.

That would leave the Senate at 49 Democratic seats and 49 Republican seats.

Just Nevada and Georgia are yet to be decided.

The vote count in Nevada is neck and neck, while Georgia’s race will be settled by a run-off election next month.

If Democrats win either of the two remaining races they will remain in control of the upper chamber of Congress because the US vice-president can cast a tie-breaking vote on their behalf.

Republicans could still take control of the US House of Representatives as votes continue to be tallied from a handful of districts after Tuesday’s elections.

If the Republicans win either or both chambers of Congress they could thwart much of Mr Biden’s agenda.

Mr Kelly, a former astronaut whose wife, Gabby Giffords, survived an assassination attempt when she was a US lawmaker, was first elected two years ago to serve out the remainder of the late John McCain’s Senate term.