Sen. John McCain, R-Ariz., said Sunday that in some parts of the country, the fall elections may turn out to be a referendum on the war in Iraq.

"Most of the time we know these elections are local, but it's beginning to look more like some of them may be global as far as they are impacted by Iraq," he said. "We've got to fight hard. We've got to win. We need to keep both houses of Congress."

McCain predicted Republicans will retain control of the Senate but said it is too early to tell if they can keep the House.

"This is a very tough election coming up," he said.

"The war is difficult. The president is not getting enough credit for a good economy which we have today," he said.

McCain, a potential presidential candidate for 2008, appeared on NBC's "Meet the Press."