If the U.S. had involved Russia and China more in Syria talks, Sen. Rand Paul said Sunday there's a possibility Bashar Assad "could already be gone."

"I think the failure of the Obama administration has been we haven't engaged the Russians enough or the Chinese enough on this," the Kentucky Republican said on NBC's "Meet the Press."

"The Russians have every reason to want to keep their influence in Syria, and I think the only way they do is if there's a change in government where Assad is gone" but other current members remain, Paul said. "That would also be good for the Christians." He noted earlier that Assad has protected Christians "for decades."

The senator went on to say that a failure to do so could result in an Islamic state that could persecute Christians in the country.And Russia, he said, could have an influence on the country if they told the government "no more weapons."