US President Donald Trump on Monday urged Florida election officials to end a recount and declare his fellow Republicans the winners of disputed races in last week's midterm elections as a judge urged both parties to be careful with claims of fraud.

As Florida officials scrambled to review more than eight million ballots by Thursday, Trump, without providing evidence, cast doubt on the recount process.

Leads by the Republican candidates in the races for a seat in the US Senate and for the governor's office shrank as more ballots were tallied following last Tuesday's election. State law mandates recounts in elections where margin of victory is within 0.5 percentage points.

Trump called for an end to the recount even though state rules allow election officials to wait 10 days for absentee ballots submitted by registered voters living outside the United States, including active-duty military personnel.

A machine recount began over the weekend in the race between outgoing Republican Florida Governor Rick Scott and Democratic US Senator Bill Nelson, with another recount underway for the Florida gubernatorial race between Republican Ron DeSantis and Democrat Andrew Gillum.

Republicans are eager to cement victories in a key battleground state after maintaining their control of the US Senate in last week's midterm congressional elections, while Democrats are eyeing another possible state governorship win. Both parties accused the other of trying to subvert democracy.

Scott on Sunday had asked a Broward County judge to issue an emergency injunction calling for law enforcement to seize all voting machines, tallying devices and ballots when they are not being used until the end of the recount and any related litigation.

The judge rejected that request on Monday, according to Marc Elias, an attorney representing the Nelson campaign. The Scott campaign did not immediately respond to a request for comment.