US Secretary of State Marco Rubio says the US expects to finish its operations in Iran “in the next couple of weeks”.

The objectives were being achieved and were ahead of schedule, he said at the end of a meeting in France of foreign ministers from the group of major Western economies, known the G7.

Referring to peace talks that President Donald Trump says Iran wants – which Tehran denies – Rubio said there had been messages, but it was unclear who was left to represent the country.

Several top Iranian leaders have been killed since the US and Israel began the war on 28 February. In the meantime, the US is sending troops to the area to give the president options, Rubio said.

Trump and his top officials have consistently said their operations in Iran would last four-to-seven weeks.

As the fourth week is about to end, Rubio’s time frame would fit with those predictions – although he also mentioned that it was a question of “weeks, not months” when he answered a series of questions from reporters.

Trump is widely reported to have passed on to the Iranians – via Pakistan – an outline of a 15-point plan to end the war.

However, when asked by reporters if the Iranians were going to give their response on Friday, the US secretary of state said: “We haven’t gotten it yet. Look, we’ve got messages. We’ve had an exchange of messages and indications from the Iranian system, whatever’s left of it, about a willingness to talk about certain things.

“We’re waiting for further clarification about who was it that we would be talking to, what we would talking about, and when will we be talking.”

Trump’s special envoy Steve Witkoff later said he was “hopeful” there would be meetings “this week”.

“We have a 15-point deal on the table that the Iranians have had for a bit of time. We expect an answer from them and it would solve it all,” Witkoff said.

Trump told reporters on Friday that he had paused a threatened attack on Iran’s power plants to give talks a chance.

“Iran is being decimated,” he said, adding: “We are talking now. They want to make a deal.”

On Friday, Iran said that Israel had carried out attacks on Iranian nuclear facilities as well as two of the country’s largest steel plants – prompting Foreign Minister Abbas Araghchi to threaten to exact a “heavy price”.

Iran’s Islamic Revolutionary Guards Corps (IRGC), the country’s powerful military force that underpins the regime, said it would retaliate by targeting industrial infrastructure connected to the US or Israel.

In their statement after the talks, the G7 foreign ministers called for “the absolute necessity to permanently restore safe and toll free freedom of navigation in the Strait of Hormuz”, which Iran has closed in retaliation.

It was a reference to Iran’s threat to charge a fee, Rubio said.

There have been reports that IRGC has already been charging some vessels a fee in return for secure passage. Iranian MPs are also drafting a bill, although it is in its early stages.

About 20% of the world’s oil and liquefied natural gas typically passes through the Strait of Hormuz.

Its closure has caused the price of oil to skyrocket and has raised concerns that a prolonged blockage could raise energy prices – and even lead to a severe contraction in the economies of many countries.

Most of the G7 countries, except Japan, are members of the Nato transatlantic alliance, which have so far refused to answer a call by Trump to send ships to escort vessels through the strait, angering the US leader.

Instead, they have said ending the conflict was the best way to ensure freedom of passage.

After the talks in France, Rubio said the UK was leading the work to build a coalition to ensure the strait remained free. Such a coalition, he said, would be needed for the period after the war.

He added that US allies would be more affected than the US if the Iranian threat became a reality.

Referring to the war more generally, the G7 communique called for “an immediate cessation of attacks on civilians and civilian infrastructure”.

“There can be no justification for the deliberate targeting of civilians in situations of armed conflict as well as attacks on diplomatic facilities,” it said.

The statement did not mention the warring parties by name, but its message appeared to be more targeted at Iran which, in addition to closing the strait, has also attacked civilian targets in Gulf countries allied to the US.

Tehran has sent drones and missiles towards Israel, but also most of the Arab Gulf countries where the US has military bases and other alliances.

In addition to targeting them, Iran has also hit airports, residential apartments, US embassies and energy sites in a region where most countries are world players in oil and gas production.