WASHINGTON — President Biden warned on Friday that Republicans could upend legislative victories achieved under his administration and a Democratic Congress if the G.O.P. were to win control of Congress in November’s midterm elections.

“They don’t have a platform other than to tear down what I’ve been able to do, we’ve been able to do.” Mr. Biden told an MSNBC news anchor, according to NBC News on Friday. “And I don’t know what they’re for.”

Democrats achieved a recent series of legislative victories heading into campaign season, after passing sweeping health, climate and tax legislation earlier this year. Those include an infusion of funding into America’s semiconductor industry to counter China and expanded medical benefits for veterans who were exposed to toxins from burn pits on military bases and a gun safety package.

“These last several weeks all I’m doing is saying here’s what we’re for, here’s what they’re for and make a choice and vote,” Biden said in the interview with the MSNBC journalist Jonathan Capehart. “And I think people are going to show up and vote like they did last time.”

Most recently, Mr. Biden vowed to wipe out up to $20,000 in student loan debt, which he touted on the campaign trail on Friday, noting that the program has received 22 million applications since it opened last week.

But that plan was brought to something of a halt with a ruling by an appeals court Friday on a case brought by several Republican-led states. And a number of Republicans in Congress have targeted some of the administration’s key legislative measures despite several having passed with bipartisan support.

Several House Republicans, including the ranking member of the committee that oversees entitlement programs, including Medicaid, said they would back repealing the law that reduced prescription drug costs for seniors if their party took control of the House in November.

Mr. Biden has previously warned that Republicans pose a threat to Social Security and Medicare, as Democrats paint the fate of America’s social safety net programs as a central campaign issue. He has also promised to continue to push forward on Democratic priorities in the next two years, like codifying abortion rights, strengthening gun control laws and instituting police reform, all measures that would be nonstarters with Republican majorities in the House and Senate.

“What do you think they’re going to do?” Mr. Biden said at an event last month, brandishing a copy of a plan drafted by Senator Rick Scott, Republican of Florida, that would allow Social Security and Medicare to “sunset” if Congress did not pass new legislation to extend them.

In his MSNBC interview, Mr. Biden also dismissed polls that showed that the majority of voters disproved of his handling of the economy. A recent New York Times/Siena College poll found Republicans have an edge going into November, with many citing worries about the economy, an issue on which Republican candidates have heavily campaigned.

Juggling criticism about the economy and dips in his approval rating, Mr. Biden has kept a low profile on the campaign trail, choosing to avoid rallies and instead touting his legislative victories in smaller events.

Mr. Biden reiterated to MSNBC that he intends to seek re-election in 2024, though he said he has not made a formal decision.