Visiting US Senator John McCain said in Jerusalem Monday that arming the Syrian rebels helped prevent Iran from furthering its ambitions on nuclear weapons, the Israel Army Radio reported.

Commenting on the concerns on his push to arm the rebels that the weapons could fall into the hands of militants who might eventually turn against the United States, McCain said "There are no good options."

"Would you rather have these weapons perhaps falling, some of them, into the hands of the wrong people, or would you rather have (Syrian President) Bashar al-Assad prevail and then encourage Iran to further their ambitions on nuclear weapons?" he asked.

McCain, an outspoken advocate of US military aid to Syrian rebels, has repeatedly called for US deeper involvement in the Syrian conflict, and called for arming the Free Syrian Army when he visited rebel forces in Syria in May.

Meanwhile, Senator Lindsey Graham visiting Israel with McCain also called on arming the Syrian rebels.

Graham asserted that the Obama administration's vacillation on Syria sent a wrong message to Tehran, recalling Obama's pronouncement that the use of chemical weapons in Syria would constitute the breaching of a "red line."

"The Iranians need to believe that the US is serious about stopping their nuclear program. I think our policy in Syria is sending them a mixed message," he added.