Secretary of State John Kerry, right, and Israeli Prime Minister Benjamin Netanyahu after a meeting on the Syrian conflict Sunday in Jerusalem. (JIM HOLLANDER / POOL/EPA)

The U.S. government sought to reassure Israel on Sunday that the U.S.-Russia deal to secure Syria’s chemical weapons does not diminish American resolve to prevent Iran from gaining a nuclear weapon.

Secretary of State John F. Kerry flew to Israel to personally brief Prime Minister Benjamin Netanyahu on what he called “the most far-reaching chemical weapons removal ever.”

“We cannot have hollow words in the conduct of international affairs, because that affects all other issues, whether Iran or North Korea or others,” Kerry said after talks with Netanyahu.

President Obama told ABC’s “This Week” in an interview broadcast Sunday that Iran understands that its nuclear program is “a far larger issue for us” than the use of chemical weapons in Syria and that the threat a nuclear-armed Iran would pose to Israel “is much closer to our core interests.” He said he was in “indirect” communication with the Iranian leadership.

Obama said Iran should not draw the wrong conclusion from his decision to back off from a missile strike against Syria. “My suspicion is that the Iranians recognize they shouldn’t draw a lesson that we haven’t struck [Syria], to think we won’t strike Iran,” Obama said.

Israel has reacted cautiously to the chemical weapons deal, under which Syria is to sign and ratify the 1993 Chemical Weapons Convention and submit to inspections and, ultimately, destruction of its weapons. The agreement came after a chemical weapons attack on a Damascus suburb that U.S. officials have estimated killed 1,400 people.

Israel’s security establishment fears that a failure to punish Syria for its use of chemical weapons could encourage Tehran, Syria’s ally, to continue to enrich uranium for a bomb.

And Israeli diplomats worry that the push for inspections of Syria’s chemical arms could throw an unwelcome spotlight on the secretive chemical and nuclear arsenal that Israel has built next door.

Netanyahu told Kerry that he supports U.S. efforts to force Syria to give up its stockpile of chemical weapons.

“The Syrian regime must be stripped of all its chemical weapons,” said Netanyahu, standing beside Kerry after their meeting. “That would make our entire region a lot safer.”

But earlier in the day, Netanyahu sounded a note of skepticism.

“We hope the understandings that have been achieved between the U.S. and Russia regarding Syria’s chemical weapons will show results, and these understandings will be tested by results — the full destruction of the stocks of chemical weapons that the Syrian regime has used against its own people,” Netanyahu said in remarks to commemorate the 40th anniversary of the 1973 Arab-Israeli war, when Israel came under surprise attack from Syria and Egypt.

What chemical weapons does Syria have?

“We must also judge the results of the efforts of the international community to stop Iran’s nuclear armament,” he said. “Here as well, it is not words that will determine the outcome but rather actions and results.”

Kerry heads next to Paris for discussions about the Syria deal with foreign ministers from France, Britain, Saudi Arabia and Turkey.

Widespread skepticism

Netanyahu’s caution appears to be shared by the Israeli public. In a poll published by the newspaper Israel Hayom, three-quarters of Israeli Jews said they did not believe Syria would give up its chemical weapons — and 65 percent said Obama would not succeed in preventing a nuclear Iran.

Israel, which is presumed to have nuclear weapons and is suspected of at least some chemical weapons capability, is worried that the Syria deal could reinvigorate calls that the entire Middle East be rid of weapons of mass destruction.

That theme is likely to run through much of the discussion of the Syria chemical weapons arrangement during the annual U.N. General Assembly this month.

In the past, Russian President Vladimir Putin has said that Syria’s chemical weapons exist as a response to Israel’s military capabilities.

Israel signed the Chemical Weapons Convention in 1993. That signals a country’s intent to abide by an accord but does not bind it to do so. Israel never ratified the treaty, which would require it to meet all its obligations. It has not acknowledged possessing chemical weapons.

Netanyahu’s deputy foreign minister, Zeev Elkin, said in an interview Sunday that Israel did not intend to ratify the convention now, because its neighbors still cannot be trusted.

“We are still facing these issues — such as calls to destroy the state of Israel from countries that still have access to these kinds of weapons,” he said.

Emily Landau, an expert in arms control at the Institute for National Security Studies in Tel Aviv, said Israel’s wariness is understandable. In 2005, Syria told the United Nations in formal declarations that it had no chemical weapons — but Syrian officials reversed themselves this past week.

A shift in perspective

Israel’s military and diplomatic establishment was initially disappointed when Obama decided not to launch a military strike to punish Syria for its use of chemical weapons.

Since then, Israel has begun see some advantages in the ­Russia-brokered diplomatic deal.

“The American threat against Syria has given Israel a present that it could only dream of — the destruction of the Syrian chemical weapons arsenal,” said Eitan Barak, an expert on arms control and disarmament at Hebrew University of Jerusalem.

For years, Barak said, Israel has invested millions in gas masks and shelters designed to resist a chemical attack. “And suddenly, all that is gone.”

But, he acknowledged, Kerry or others might now ask Israel to ratify the chemical weapons treaty.

“The finger will point toward Israel, and in the view of many people around the world, that is rightly so,” he said.

Most of the world’s countries are party to the chemical weapons treaty. Only Israel and Burma have signed but not ratified it. Barak said it would be a relatively straightforward matter for Israel to ratify the treaty because the government can do so on its own — Netanyahu does not need a vote in parliament.

Avigdor Lieberman, former foreign minister and chairman of the Israeli Knesset’s Foreign Affairs and Defense Committee, told Channel 2 on Sunday morning, “Only in the next week, when Syria has presented a list of its chemical weapons stockpiles to the U.N., will we know if Assad is serious. Israel has a pretty good idea about the weapons in the hands of Assad, and after the published data, we will verify them.”

With both Syria and Iran, Netanyahu said, “if diplomacy has any chance to work, it must be coupled with a credible military threat.”

Kerry said his goal in the Syria deal is to set a ”standard of behavior” that would also apply to Iran or North Korea or any other state that “might try to reach for these kinds of weapons.”

The United States is retaining its option of a unilateral attack on Syria if the Assad government does not comply with the agreement on chemical weapons.

“Diplomacy has always been the preferred path,” Kerry said. “But make no mistake, we’ve taken no options off the table.”

Ruth Eglash contributed to this report.