GENEVA, Switzerland (AFP) — The United States (US) is “complicit” in Israel’s strikes in Iran, Tehran’s ambassador to the United Nations (UN) claimed Wednesday, vowing that his country would respond if Washington crosses a “red line”.

After decades of enmity and a prolonged shadow war, Israel says its surprise air campaign that began on June 13 is aimed at preventing Iran from acquiring nuclear weapons — an ambition Tehran denies.

Iran said early Wednesday that it fired hypersonic missiles at Israel in the latest round of overnight strikes between the arch foes.

US President Donald Trump has said that Washington has played no part in the bombing campaign by its ally Israel, but has also warned Iran that his patience is wearing thin.

“We firmly believe that the United States is complicit in what Israel is doing,” Iranian ambassador Ali Bahreini told a press conference.

“And at any time, at any point, if we come to the conclusion that the United States is directly involved in attacks against Iran, we will start responding to the United States.”

He said Tehran was “vigilant” about Trump’s “completely unwarranted” and “hostile” remarks.

“There is a line which, if crossed, there should be a response on our side… once the red line is crossed, the response will come,” Bahreini said.

“We will respond strongly and we will stop aggression from any side, be it Israel or the United States,” he told the UN correspondents’ association.

“And we have given a message to the United States that we will respond very firmly and will stop the aggression by anybody — including the United States.

Bahreini also said Tehran was “resolute in responding to Israeli attacks”.

“We will respond very, very, very seriously and strongly, and that is what we are doing now. Nobody should expect Iran to show any kind of restraint,” he said.

He also criticised the attitude of Western and European nations.

“Not only they are not condemning the attacks and aggression, they are trying to justify the aggression,” he said.

Asked about a possible resumption of negotiations with Washington over Iran’s nuclear programme, the ambassador said that for now, Iran was “not thinking about any scenario” other than “defending ourselves”.

Addressing the UN Human Rights Council on Wednesday, Bahreini issued a warning to Israel’s allies.

“The Israeli regime’s supporters, and the United States at the forefront, should know that supporting this regime means directly supporting international humanitarian and human rights law violations,” he said.