The three day meeting ended with no significant deal on promoting global trade.
On the sidelines, the European Union and the South American trading bloc known as Mercosur did however announce they were close to concluding a free trade accord under negotiation since the 1990s. It might be ready early next year, they said.
But the broader WTO gathering was seen as a dud.
"We are disappointed. Despite our efforts, members failed to reach any significant agreements," said WTO Director-General Roberto Azevedo.
He took a jab at what he called the US delegation's inflexibility, saying "multilateralism does not mean getting what you want, but rather that which is possible."
As has been the case for years, bilateral deals took precedence over multilateral accords, which are hard to achieve because they require consensus within the WTO.
A fisheries agreement had shaped up as a possible major accord at this meeting, but it was blocked by India, according to an NGO called Bloom.
"Buenos Aires should serve as a wakeup call. The result is not satisfactory," said France's secretary for foreign trade, Jean-Baptiste Lemoyne.
Trump has already withdrawn the United States from the Trans-Pacific Partnership (TPP) and insisted on renegotiating the North American Free Trade Agreement (NAFTA) with Mexico and Canada.
And on Monday, US Trade Representative Robert Lighthizer accused the WTO of losing its focus on trade negotiation.
"Too often members seem to believe they can gain concessions through lawsuits that they could never get at the negotiating table," Lighthizer said.
He also criticized special treatment given to some countries because they are classified as developing nations.
Trump has long made the WTO a preferred target of its "America First" policy, threatening to pull Washington out of the trade organization it says is hampering its ability to compete.
Lighthizer did not even stay for the end of the WTO conference, leaving a day early.