Venezuela’s foreign minister said on Wednesday the United States was trying to overthrow the government of Nicolas Maduro and suggested talks with U.S. President Donald Trump — an idea the Trump administration immediately rejected.

Jorge Arreaza, addressing the U.N. Human Rights Council, suggested that Maduro and Trump meet to “try to find common ground and explain their differences.” He also said his country had lost $30 billion in assets “confiscated” since November 2017 under sanctions.

U.S. Vice President Mike Pence ruled out prospects of talks. “The only thing to discuss with Maduro at this point is the time and date for his departure,” Pence said on Twitter.

“For democracy to return and for Venezuela to rebuild — Maduro must go,” Pence said.

Dozens of diplomats, mainly from Latin American countries, walked out as Arreaza began to speak, while some European ambassadors boycotted the speech.

The United States and dozens of other nations have recognised opposition leader Juan Guaido as Venezuela’s legitimate president, but Maduro still controls the military, state institutions and oil company Petroleos de Venezuela SA , which provides 90 percent of the country’s export revenue.

Maduro also “stands ready for dialogue” with the Venezuelan opposition, Arreaza said.

“There is an attempt by external powers to overthrow an elected government, this goes against all rules of international law,” Arreaza said.

‘Ilegal pillage’

The United States targeted Venezuela’s government with new sanctions on Monday and called on allies to freeze the assets of state-owned PDVSA after deadly violence blocked humanitarian aid from reaching the country over the weekend.

The “blockade” against Caracas amounts to “theft of the assets and gold” of Venezuela, Arreaza said.

Some $30 billion in state assets had been confiscated since November 2017, he said, adding: “This is the illegal pillage of the resources of our state oil company in the United States.”

U.S. refiner Citgo Petroleum Corp is cutting ties with its parent PDVSA to comply with U.S. sanctions imposed on the OPEC country, two people close to the decision told Reuters on Tuesday.

The Bank of England has blocked $1.5 billion and Belgium $1.4 billion, Arreaza said. The Bank of England has previously declined to comment on questions about Venezuela’s gold, citing client privacy considerations.

“The humanitarian crisis is being used as a pretext for foreign intervention in my country,” Arreaza said.

In weekend clashes at the Colombian border, Venezuelan security forces acted with “proportionality and caution,” as humanitarian aid was burned, he said.

Earlier, an aide to President Ivan Duque of neighboring Colombia called for action to end Venezuela’s humanitarian crisis and bring about a political transition leading to free elections.