VALDAI, Russia – Russian President Vladimir Putin said Thursday he cannot vouch that Syria will surrender its chemical weapons arsenal and suggested that Israel could help assure the success of the U.S.-Russian deal by surrendering its alleged nuclear weapons.

“I don’t know whether we will manage to persuade” Syrian President Bashar Assad to go along with the plan, Putin said at the Valdai Discussion Club, an annual Russian political forum. “Up to now everything looks as if Syria completely agreed with our plan. But I can’t say whether we will manage to complete the process by 100 percent.”

Putin implied that the prospects for peace and chemical weapons disarmament in Syria would be bolstered if Israel gave up its own suspected cache of nuclear arms, believed to be the only such arsenal in the Middle East.

“Syria came into possession of chemical weapons as an alternative to Israel’s nuclear weapons,” Putin said at the gathering of political analysts and experts in Valdai, about 250 miles northwest of Moscow. “The technological superiority of Israel in the region is so obvious that it doesn’t require nuclear weapons, which makes (Israel) a target and creates a special problem for it.”

Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov reached the deal to eliminate the Syrian arsenal after a series of chemical weapons attacks against civilians near Damascus last month that the United States and its allies say were carried out by Syrian troops.

Meanwhile, in Syria, al-Qaida militants seized a town near the Turkish border Thursday after expelling Western-backed rebels from the area, demonstrating the growing power of jihadis as they seek to expand their influence across opposition-held Syrian territory.

The infighting threatened to further split opposition forces outgunned by President Bashar Assad’s troops and strengthen his hand as he engages with world powers on relinquishing his chemical weapons.

Opposition forces who had been hoping that U.S.-led military strikes would help tip the balance in the civil war are growing increasingly desperate after the Obama administration shelved those plans in favor of a diplomatic solution.

Many rebels blame jihadis in their ranks for the West’s reluctance to intervene militarily in Syria or give them the advanced weapons they need.