US President Donald Trump campaigned in Georgia on Saturday for two Republican senators at a rally that some in his party feared could end up hurting, not helping, their chances by focusing on his efforts to reverse his own election defeat. In his first rally appearance since he lost to Democrat Joe Biden in the November 3 presidential contest, the Republican Trump reminded the chanting crowd that he came to southern Georgia to persuade them to vote Republican in runoffs on January 5. But he quickly turned to his repeated claims, made without evidence, of widespread fraud in the presidential election. "They cheated and rigged our presidential election but we'll still win it. And they are going to try to rig this election too," Mr Trump told the crowd in Valdosta, who chanted "We love you!" and "Four More Years!" He repeated his attacks on Republicans who have refused to back him, including Georgia's governor, Brian Kemp. Earlier on Saturday, Mr Trump phoned Mr Kemp and pressured the governor on Twitter to take further steps to help him overturn the election results. The outgoing president's claims of widespread voter fraud have been rejected by state and federal officials across the country, and his campaign's numerous legal challenges have almost all failed. Mr Biden was the first Democratic presidential candidate to win in Georgia since 1992. Statewide recounts, including a painstaking review by hand of some 5 million ballots, turned up no significant irregularities. The January runoffs pit two Republican senators, David Perdue and Kelly Loeffler, against well-funded Democratic challengers Jon Ossoff and Raphael Warnock, seeking to capture a state that has not elected a Democratic senator in 20 years. The races will determine which party controls the US Senate. Democrats, who already have the majority in the House of Representatives, need to win both seats to control the Senate. If Republicans win one seat, they will retain their majority and be able to block much of Mr Biden's legislative agenda. Mr Biden said he would visit Georgia to campaign for the Democratic candidates but did not give a timetable for his trip. Attacking Republicans Governor Kemp did not attend the rally due to the death in a car crash of Harrison Deal, a close family friend of the governor and staffer for Ms Loeffler. He had an active exchange with Mr Trump on Twitter earlier in the day, however. "I will easily & quickly win Georgia if Governor @BrianKempGA or the Secretary of State permit a simple signature verification ... Why are these two 'Republicans' saying no?" Mr Trump wrote on Twitter. After Mr Kemp responded that he had "publicly called for a signature audit three times," Mr Trump said that wasn't good enough, and added in a second tweet that Mr Kemp should immediately call a special session of the state legislature. "Your people are refusing to do what you ask. What are they hiding?" Mr Trump said. In a move unprecedented in modern US history, the Trump team has tried, without success, to get Republican-controlled legislatures in battleground states won by Mr Biden to set aside the results and declare Mr Trump the winner. Mr Biden won the election with 306 Electoral College votes - more than the 270 required - to Mr Trump's 232. The Electoral College will meet on December 14 to formalise the outcome. Mr Trump told the Saturday rally his challenge was headed to the US Supreme Court "very shortly," without elaborating. Legal experts do not see a path to the nation's highest court, however. Richard Hasen of the UC Irvine School of Law said it was unclear what case Mr Trump was referring to, but added: "I don't think any of these efforts stand any chance of success."