Their announcements put them squarely in President Trump's corner as the Senate weighs a newly passed House measure that would raise coronavirus relief payments to most Americans from $600 to $2,000.
Asked on "Fox & Friends" on Tuesday if she would back Trump's repeated calls for greater relief, Loeffler said she was "proud to do that."
"The president has fought for our country from day one. He continues to fight for every single American. I’ve stood by the president 100 percent of the time," she said. "I’m proud to do that and I’ve said absolutely we need to get relief to Americans now and I will support that."
Following her appearance on Fox & Friends, Loeffler tweeted, "I agree with @realDonaldTrump — we need to deliver $2,000 direct relief checks to the American people."
Perdue also announced in an interview on "America's Newsroom" that he would support raising the payments to $2,000.
"I'm delighted to support the president in this – it's really a $1,400 increment over what we've already done," Perdue said. "And I think with the vaccine coming, I think this is absolutely appropriate, so I fully support what the president is doing right now … It's the right thing to do for the people in Georgia."
Trump signed a $900 billion coronavirus relief bill into law on Sunday, despite sharply criticizing its $600 direct payments to most Americans as insufficient. He tweeted Tuesday that Americans had "suffered enough" and deserved more relief.
Loeffler, in a tight race against Democratic candidate Rev. Raphael Warnock, first said last week that she would consider voting for the new figure, which Democrats originally pushed in the stimulus package if it diverted funds away from "wasteful spending."
On Tuesday, Loeffler pointed out what she thinks is an "issue" as it pertains to her opposing party.
"Democrats have blocked relief time and again," she told "Fox & Friends" on Tuesday. "That’s why we’re in this situation as a country."
Loeffler went on to say Republicans have "tried to pass that relief this summer," but House Speaker Nancy Pelosi, D-Calif., and Sen. Bernie Sanders, I-Vt., "held it up because they were playing politics with the lives of Georgians and all Americans around this election."
The House on Monday passed a measure in the $900 billion COVID-19 relief package that Trump signed on Sunday night to give Americans making up to $75,000 direct payments of $2,000 – rather than an initial proposal of $600 – but it is unclear whether the Senate will vote to do the same.
Loeffler and Perdue voted for the original coronavirus bill last week and praised Trump for signing it, but their Democratic challengers Warnock and Jon Ossoff called on them to support Trump's call for the larger payments.
Senate Minority Leader Chuck Schumer, D-N.Y., is also pressuring Senate Majority Leader Mitch McConnell, R-Ky., to bring the measure to the floor, which has enthusiastic Democratic support. Only four Senate Republicans have said thus far they support the $2,000 checks: Loeffler, Perdue, Sen. Josh Hawley, R-Mo., and Sen. Marco Rubio, R-Fla.
It would need 60 votes to pass, meaning Democrats will need at least eight more Republicans on their side.
The announcements come as Trump prepares for perhaps his final campaign stop as president next week in Georgia. Perdue and Loeffler are counting on turning out Trump supporters to win the runoffs, which will determine Senate control.
Perdue called him and Loeffler the "last line of defense" against a Democratic Senate majority under President-elect Joe Biden.
While Trump narrowly lost Georgia, Perdue finished two points ahead of Ossoff in the general election and fell just short of the 50% threshold to avoid the runoff. Warnock won the plurality of the vote in the "jungle" special election against Loeffler and more than a dozen others, but Republican candidates won more votes than their Democratic counterparts in the race.
"We have to hold Democrats accountable on Jan. 5 because that’s what’s on the ballot," Loeffler said. "Who is going to fight for the American people? That’s what Perdue and I have been doing since day one and we’re going to continue to do that."
Fox News’ Audrey Conklin, Paul Steinhauser and Caitlin McFall contributed to this report.