"It's in their interest to help," Rubio said shortly before heading to France where he will attend a meeting of G7 foreign ministers outside Paris on Friday.

It is Rubio's first trip abroad since the United States and Israel launched airstrikes on Iran on February 28.

Rubio, who skipped the first day of G7 talks on Thursday, said there was "progress" in talks with Iran, but refused to speculate on when or how they might end.

"There are intermediary countries that are passing messages, and progress has been made," Rubio said, calling it an "ongoing process."

Britain, Canada, France, Germany, Italy and Japan -- the other G7 members -- on Thursday signaled their hope for a diplomatic solution to the situation in Iran, which has rippled through the global economy due to the virtual closure of the Strait of Hormuz.

Around a fifth of global crude oil and liquefied natural gas passes through the waterway in peacetime.

US President Donald Trump said earlier Thursday at a cabinet meeting that Tehran was more keen to make a deal than he was, noting that the military operation was ahead of schedule and reiterating his criticism of NATO.

At the same meeting, Rubio said Washington's allies should be grateful to Trump for undertaking the offensive, led in coordination with Israel.

"The president is not just doing a favor to the United States and to our people. This is for the world," Rubio said.

France currently holds the rotating presidency of the G7.