The Arizona senator was also asked about comments by President Obama at a fundraiser in New York City where he said McCain would be "considered too liberal" to "get a nomination in the Republican Party this time out." McCain dismissed the comments, saying he was "closely aligned" with presumptive front-runner Romney.
"I think Mitt Romney and I are very closely aligned in most of our views, and the fact is there are independent voters who decide elections now, and we need to make sure we reach out to them as well as preserve our conservative base," McCain said.
That discussion pivoted into a critique of President Obama's foreign policy ahead of a meeting scheduled between the president and Israeli Prime Minister Benjamin Netanyahu on Monday in Washington. Obama is expected to urge the prime minister to exercise restraint with Iran, which is suspected of working to obtain a nuclear bomb.
McCain argued that Obama had "the worst relations with Israel of any president in recent history" and that his administration failed to grasp the severity of the Iranian threat.
"The chairman of the Joint Chiefs of Staff said Iran is, quote, 'rational.' A country that says it's going to wipe another country off the map is rational?" McCain said.
The senator went on to argue that President Obama was taking the wrong approach in prescribing restraint.
"This is a flawed policy. This is a president who doesn't understand what our national-security interests are," McCain said.