With recounts underway and legal challenges intensifying, President Donald Trump on Monday demanded that the tight Florida races for governor and the state's seat in the U.S. Senate be called for Republicans because an "honest vote count is no longer possible."

"The Florida Election should be called in favor of Rick Scott and Ron DeSantis in that large numbers of new ballots showed up out of nowhere, and many ballots are missing or forged," Trump said in a post on Twitter, without citing any evidence for his dramatic claims.

State election monitors have said there is no evidence of voter fraud, and the agency tasked with overseeing election integrity said it had not received any allegations in writing, despite accusations from Republicans.

Trump tweet

Florida started a contentious ballot recount over the weekend in its tight Senate and gubernatorial races. In a state where a recount — and subsequent Supreme Court case — decided the 2000 presidential election, the process has already become bitter and prompted Republicans to accuse their opponents of attempting to "steal" the races.

Before the recount, Republican Gov. Rick Scott led Democratic Sen. Bill Nelson by 0.2 percentage points, or about 13,000 votes. The contest will help to set the partisan composition of the Senate, which is critical of Trump's ability to put conservative judges on federal benches. The GOP is projected to keep its majority in the Senate, but a Scott win would help the party expand its control of the chamber.

NBC News has said the Senate race too close to call. Nelson on Monday called for Scott to recuse himself from "any role" in the recount process, saying it "is the only way that we can ensure that the people's votes are protected."