World powers say they are increasingly worried that Iran is using its nuclear program to develop military weapons.

The five permanent U.N. Security Council members and Germany Thursday issued a resolution expressing “deep and increasing concern” about the issue.

The resolution was put forward at a meeting of the International Atomic Energy Agency in Vienna. The watchdog agency's board of governors is expected to debate the measure on Friday.

The meeting is the first for the agency since it alleged last week that there is “credible” evidence Tehran is trying to build nuclear weapons.

Earlier Thursday, IAEA chief Yukiya Amano said he wanted to send a high-level mission to Iran to see if its controversial nuclear program has “possible military dimensions.”

Amano said he put the request in writing to Iran's top nuclear officials earlier this month, and that he hoped a date can be agreed upon soon.

The United States and several European countries have been pushing for the nuclear watchdog to come down hard on Iran for its nuclear program. But Russia and China have expressed skepticism about last week's IAEA report. Russian officials dismissing the findings as nothing new.

Iran rejected the report and has continually denied allegations it is pursuing nuclear weapons.

Recent reports in the Israeli media said Israel's government has been considering a military strike on Iran's nuclear sites. And Israeli Defense Minister Ehud Barak warned during a U.S. television interview that Iran could spark a new, nuclear arms race if it gets a nuclear bomb.

Iran's Supreme Leader Ayatollah Ali Khamenei has said Tehran will respond to any military strike by Israel or its main ally the United States with “strong slaps and iron fists.”

The U.N. Security Council has passed four sets of sanctions on Iran for refusing to stop nuclear activities that have both civilian and military uses.