MAR DEL PLATA — Trade and investment ministers from G20 countries meeting in Argentina said there was an "urgent need" to improve the World Trade Organization, a joint statement said on Friday.

With US President Donald Trump readying tariffs on another $200 billion in Chinese goods, the ministers said they were "stepping up the dialogue" on international trade disputes, according to the statement issued at the summit.

It did not provide any details of possible WTO reforms or how dialogue on trade was being increased.

"Obviously the new tariff measures are not positive," Argentina's Production and Labor Minister, Dante Sica, said in a news conference at the end of the one-day meeting. "But we need to see how things evolve."

German Deputy economy Minister Oliver Wittke said the joint declaration sent a powerful signal about the importance of strengthening WTO "especially in times of 'America first' and increasing global protectionism," with next steps to follow when G20 leaders meet in Argentina at the end of November.

"We have to use this momentum," Wittke said in a statement released by the ministry after the summit.

Outside the meeting, smoke filled the air in the normally tranquil seaside city of Mar Del Plata where the conference is being held. Protesters burned makeshift American flags and chanted against free trade orthodoxy and Trump's support of Argentina's cash-strapped President Mauricio Macri, whose fiscal belt-tightening has garnered a backlash from the country's working-class.

"We're standing here in solidarity with the workers of Latin America. While those politicians sleep in fancy beds, communities starve because of trade and adjustment policies that hurt the most vulnerable," protester Maralin Cornil, 30, said.

Argentina holds the G20's rotating presidency this year, and is re-negotiating a $50 billion stand-by financing deal with the IMF, cutting its fiscal deficit targets and reducing costs to ensure it can continue paying its international debts.

Trump has said he would attend the summit's final meeting with other heads of state, in Buenos Aires on November 30. — Reuters