China’s ambassador to Chile has derided U.S. Secretary of State Mike Pompeo, saying he “lost his mind” when he blamed China for the meltdown in Venezuela.

Xu Bu made the remarks in an interview published Sunday in the Chilean newspaper La Tercera following Pompeo’s attack on China last week while visiting four South American nations.

Tensions are ratcheting up between the nations as the Pentagon explores possible military options to deter Chinese, Russian and Cuban influence in Venezuela, CNN reported Monday.

The Trump administration recognizes opposition leader Juan Guaido as Venezuela’s self-declared interim president and has imposed sanctions wreaking increasing hardships in the country to drive out embattled President Nicolás Maduro.

Pompeo last week scorched Beijing for continuing to back Maduro. “China’s bankrolling of the Maduro regime helped precipitate and prolong the crisis in that country,” said Pompeo, who called Maduro a “power-hungry tyrant.”

China is Venezuela’s biggest foreign creditor and is estimated to have provided up to $62 billion in loans since 2007, The Guardian reported.

A spokesman for China’s Foreign Ministry criticized Pompeo’s “groundless allegations” and “attempts to ... sow discord between China and Latin American countries.”

The U.S. “has long been treating Latin America as its backyard, where it would resort to willful use of pressure, threat or even subversion .... I am sure Latin American countries are fully capable of telling a true friend from a false one who is ignoring rules and spreading chaos,” spokesman Lu Kang said at a Beijing news conference Monday, according to an official transcript.

Some 3 million Venezuelans — 10% of the population — have fled the country over the last three years amid hyperinflation, food shortages and other hardships.

It wasn’t immediately clear how the confrontation may affect the relationship between China and the U.S. as the two countries continue to work on a trade deal that the White House has said for months is close to completion.