Iran on Friday declared it would not discuss the future of its nuclear program while facing Israeli attacks, as Europe pushed to bring Tehran back to the negotiating table, with a decision on U.S. involvement expected within two weeks.

Israel launched strikes on Iran last Friday, aiming to halt its longtime adversary’s nuclear weapons development. Iran responded with missile and drone attacks on Israel, insisting its nuclear program is peaceful.

Israeli air raids have killed 639 people in Iran, including top military leaders and nuclear scientists, according to the Human Rights Activists News Agency.

Israel says Iranian missile attacks have killed at least two dozen Israeli civilians.

Reuters could not independently verify casualties on either side.