McCain said on CBS' "Face the Nation" the fighting between Israeli forces and Hamas was a different situation than previous flare-ups and the United States could not count on it being resolved in the same way.
"The United States, obviously, should be as heavily involved as they possibly can," said McCain, the ranking Republican on the Senate Armed Services Committee. "I'm not sure how much influence that this administration has."
McCain chided the Obama White House for being too insistent on a Palestinian peace process that he said is producing little in the way of progress. He cautioned the Arab Spring had shuffled the players in the region.
McCain advised the United States not to place any preconditions on Israel, such as a settlement freeze, while hammering out an agreement.
He suggested sending a high-profile senior official such as former President Bill Clinton to the region to take part in the negotiations.
"We need a person of enormous prestige and influence to have these parties sit down together as an honest broker," McCain said. "But we have a lot of work to do to regain some credibility because we're crumbling all over the Middle East."