WASHINGTON Republican Kari Lake, a former Arizona gubernatorial candidate who has echoed former President Donald Trump's false claims about fraud at the 2020 election, will announce a 2024 bid for the U.S. Senate, the Wall Street Journal reported on Thursday, further complicating a potential three-way race in the battleground state.

Lake is set to launch her campaign challenging independent incumbent Senator Kyrsten Sinema on Oct. 10, she told the newspaper in an interview. Representatives for Lake could not immediately be reached for comment.

Arizona, which Democrat Joe Biden narrowly won in the 2020 presidential race, could help tip the balance in the divided Senate. It is also one of six states that could swing either to Republicans or Democrats in presidential votes, potentially playing a decisive role as Biden seeks a second term in office.

Lake has aligned herself with Trump, the frontrunner for the Republican presidential nomination. A former television news anchor, Lake lost her 2022 bid for governor but has refused to concede the race despite losing legal challenges.

"We need to get a senator in there who is going to fight back and put America first," Lake told the Journal.

Democrats currently hold the Senate 51-49, including Sinema and two other independents who caucus with them.

Democratic U.S. Representative Ruben Gallego is also challenging Sinema, who left the Democratic Party in December and has not yet announced her re-election plans.

Lake also faces Republican competition. Mark Lamb, sheriff for Arizona's Pinal County, is seeking the Republican nod, the Journal reported. Blake Masters, a far-right Republican who lost his 2022 challenge to Arizona's other U.S. senator, Democrat Mark Kelly, could also seek the nomination.

It's unclear whether Lake could win support from Senate Republican Leader Mitch McConnell, who has repeatedly drawn Trump's ire. Lake told the Journal she will be in Washington next week and hopes to meet with the Senate's top Republican, adding that she would back him as leader.

Meanwhile, Biden will use a Thursday appearance in Arizona to warn of the threat U.S. democracy faces from far-right MAGA Republicans, referring to Trump's Make America Great Again slogan. Independent voters have also expressed concerns over Trump's election fraud claims and legal woes.

(Writing by Susan Heavey; editing by Rami Ayyub and Alistair Bell)