New York, June 22 : US Vice-President J.D. Vance declared on Sunday that his country was not at war with Iran but only with its nuclear programme, leaving the door open for diplomacy.

President Donald Trump was certain to respond if Tehran was interested in a peaceful settlement.

"We're not at war with Iran," Vance told two interviewers using identical words.

"We're at war with Iran's nuclear programme."

Speaking on the morning after "Operation Midnight Hammer" attacking Tehran's three nuclear facilities, Vance told ABC News, "I think the President took decisive action to destroy that programme last night."

He ruled out trying to topple the Iranian Supreme leader Ayatollah Ali Khamenei.

"We don't want to achieve regime change," he said on ABC News.

On the possibility of a peaceful solution, Vance told NBC News, "We didn't blow up diplomacy," but "diplomacy never was given a real chance by the Iranians".

He said sarcastically, "The Iranians are clearly not very good at war."

"Perhaps they should follow President Trump's lead and give peace a chance," he added.

"If they're serious about it, I guarantee you the President of the United States is too," he said.

He was ambivalent about the extent of the destruction of the three nuclear facilities at Isfahan, Natanz and Fordow, which Trump said on Sunday night had been "completely and totally obliterated".

Asked on ABC News if he was certain about it, Vance said, "Severely damaged versus obliterated -- I'm not exactly sure what the difference is. What we know is we set their (Iran's) nuclear programme back substantially."

"They are much further away from the nuclear programme today than they were 24 hours ago," he added.

Vance was dismissive of reports that Iran's Parliament has endorsed a move to close the Strait of Hormuz, the jugular in international energy trade.

He told NBC, "If they want to destroy their own economy and cause disruptions in the world, I think that would be their decision."

"But why would they do that? I don't think it makes any sense," he said.

However, on a Fox News programme, US Secretary of State Marco Rubio asked China to intervene to keep the strait open.

"I encourage the Chinese government in Beijing to call them about that, because they heavily depend on the Strait of Hormuz for their oil," he said.

Rubio issued a deadly warning to Iran against retaliating against the US.

"It'll be the worst mistake they've ever made."

"We're not looking for war in Iran, but if they attack us, then I think we have capabilities they haven't even seen yet," he said.

/IANS