U.S. Secretary of State John Kerry called Prime Minister Benjamin Netanyahu on Sunday with a reassuring message: the Obama administration is determined to take action against Bashar Assad's regime in response to the August 21 chemical weapons attack.

According to a senior official in the State Department, Kerry stressed during the call that the U.S. will ensure that Assad "will be held accountable."

Kerry's words of reassurance to Netanyahu came on the heels of a conversation similar in nature held between U.S. President Barack Obama and Netanyahu on Saturday. Channel 2 reported on Monday that Obama told Netanyahu that "Syria is not Iran," which is why the manner the Syrian crisis is being dealt with has no implications for the way the Iranian threat is to be handled.

A U.S. administration official has also told Haaretz that in their conversations with world leaders, and while briefing members of Congress in an effort to convince them to support military action, Obama and Kerry emphasized that a failure to act would unravel the deterrent impact of the international stand against the use of chemical weapons.

"A failure to take action… risks emboldening Assad and his key allies – Hezbollah and Iran – who will see that there are no consequences for such a flagrant violation of an international norm," he said. "Anyone who is concerned about Iran and its efforts in the region should support this action."

President Shimon Peres on Monday defended Obama's decision, expressing confidence that the U.S. not tolerate the use of chemical weapons. "President Obama has his own considerations," he said. Wars, Peres said, always look better before they are launched. The Israeli president said he has full faith in Obama's moral and operational stance. "I recommend patience. I am confident that the U.S. will respond."

Haaretz reported Sunday that senior Israeli officials stated that the talk between Obama and Netanyahu was aimed at coordinating both states' next moves regarding Syria. Roughly two weeks ago, senior U.S. government officials promised their Israeli counterparts that Israel would be notified hours in advance of any possible attack on Syria, so as to provide ample time for Israeli defense preparations against possible missile fire from Damascus.

Obama wanted to inform Netanyahu of his decision to delay the attack partially to allow Israel to make its security and military preparations accordingly.

According to reports in the American media, Obama decided to postpone the strike and ask for Congressional approval on Friday night after a tete-a-tete with White House chief of staff, Denis McDonough. Gen. Martin Dempsey, chairman of the U.S. Joint Chiefs of Staff, also advised Obama that the efficacy of a strike in Syria would not be compromised if it were put off by a few days or even a month. A few hours later, Obama phoned Netanyahu to inform him of his decision.

A senior Israeli official said on Sunday that Obama’s conversation with Netanyahu shows how closely coordinated the two countries are on the Syrian issue. However, it may be assumed that one of Obama’s reasons for the phone call was to keep Netanyahu in the picture and keep him from publicly criticizing the president’s decision to delay the strike.