Kari Lake, the close Trump ally and senior adviser to the U.S. Agency for Global Media, urged Congress on Wednesday to gut the Voice of America and other federally funded news organizations she oversees, as lawmakers of both parties expressed concern about the move.

In a hearing on Capitol Hill that grew testy at times, Ms. Lake defended proposed cuts to the global news organizations, while Democrats and some Republicans warned that they could make it impossible for the United States to disseminate information to countries with limited press freedoms, such as Iran, China and Russia.

“What is going out on V.O.A. airwaves — it’s outrageous, and it has to stop,” she told the House Foreign Affairs Committee. She called independent reporting from international news agencies funded by the government “corrupt” and “biased,” and made clear that President Trump’s goal was not to overhaul but to shut down the global media agency, which she called “a rotten piece of fish.”

Mr. Trump himself chimed in on Wednesday with a social media post, urging Congress to “kill” the Voice of America.

“Why would a Republican want Democrat ‘mouthpiece,’ Voice of America (VOA), to continue?” he wrote. “It’s a TOTAL, LEFTWING DISASTER — No Republican should vote for its survival. KILL IT!”

Mr. Trump has accused the news group of spreading “anti-American” and partisan “propaganda,” calling it “the voice of radical America.” In March, he signed an executive order that effectively called for the dismantling of the news agency, and put nearly all Voice of America reporters on paid leave, ceasing its operations for the first time since its founding in 1942.