President Trump on Thursday accused China of breaking a promise President Xi Jinping made at the G20 to buy more US farm products — ratcheting up the pressure as talks resumed over the trade war between the world’s two largest economies.

“Mexico is doing great at the Border, but China is letting us down in that they have not been buying the agricultural products from our great Farmers that they said they would. Hopefully they will start soon!” Trump said on Twitter.

After the G20 in Japan last month, the president said that he and Xi had declared a truce in their trade war so talks could continue.

Trump promised not to impose new tariffs on Chinese goods and to ease restrictions on technology company Huawei, and said Xi had vowed to buy more products grown by American farmers, though the Chinese never confirmed the hike in farm imports.

But the agreement in Osaka kick-started talks that had been stalled since May.

Chinese and US negotiators spoke by phone Tuesday and are discussing a face-to-face meeting in the future.

But no deadline has been set for the process to conclude, leaving the possibility of a protracted negotiation that lasts well into a presidential election year.

Trump has imposed 25 percent tariffs on $250 billion of Chinese goods and has pledged only to accept a deal with Beijing that includes structural reforms to the way China does business.

Beijing’s retaliatory tariffs last year on imports of agricultural goods have slammed many farmers — a key Trump constituency — forcing bankruptcies and a slowdown in farm lending as many operations struggle and fall deeper into debt.

The agricultural loan portfolios of the nation’s top 30 banks fell by $3.9 billion, to $18.3 billion, between their peak in December 2015 and March 2019, the analysis showed — a 17.5 percent decline, Reuters reported.

Washington and Beijing were close to completing a deal in May when Chinese officials balked at requirements that it change its laws to implement reforms, US officials charged.