BUENOS AIRES — Trade ministers from the Group of 20 countries said Friday that there was an “urgent” need to overhaul the World Trade Organization, which President Trump has threatened to withdraw the United States from.

The statement by the G20 ministers after a meeting in Argentina was a tacit acknowledgment by world leaders that Mr. Trump’s criticism of the W.T.O. and his tariffs have significantly weakened the international trading system. Just two years earlier, when Barack Obama was still president, the G20 trade ministers, who represent countries including China, Japan and the United States, called on world leaders to further reduce barriers to trade.

Diplomats had said they hoped to use the trade ministers meeting in Mar del Plata, a coastal city, to defuse trade tensions — and they claimed a modicum of victory on that score on Friday.

“The fact that we are talking about the reform of the World Trade Organization means that we all agree that we need to have an organization that allows us to establish rules and allows us to work within the framework of international trade,” Jorge Faurie, the foreign minister of Argentina, said at a news conference.