One day after a mysterious assassination of an Iranian nuclear scientist, U.S. President Barack Obama called Israeli Prime Minister Binyamin Netanyahu on the phone and reportedly wanted explanations.

According to Channel 2 television news, sources in Netanyahu’s bureau said the conversation was “long and good.” The White House said that the two leaders spoke, among other things, about “recent Iran-related developments, including the international community’s efforts to hold Iran accountable for its failures to meet its international obligations.”

Channel 2 said, however, that it appears Obama demanded explanations from Netanyahu following reports in the press as well as accusations by Iran that Israel was involved in the killing. The U.S. has denied involvement in the assassination.

The television report also says that Obama sought to make clear to Netanyahu American expectations from Israel regarding Iran. The U.S. reportedly wants Israel to refrain from attacking Iran and to coordinate all Iran-related actions with Washington.

The White House said Obama “reiterated his unshakable commitment to Israel’s security, and the President and the prime minister promised to stay in touch in the coming weeks on these and other issues of mutual concern.”