Sen. John McCain (R-Ariz.) and Rep. Barbara Lee (D-Calif.) came out Sunday on opposite sides of declaring a deadline for U.S. withdrawal from Afghanistan.

At 104 months long, the war in Afghanistan has eclipsed others in American history. McCain, the ranking member on the Senate Armed Services Committee, said on NBC’s “Meet the Press”: “I’m against a timetable. In wars, you declare when you’re leaving after you’ve succeeded.”

In laying out a plan for Afghanistan in December, President Barack Obama announced a surge of troops, which will reach its height this fall, then identified July 2011 as the date for beginning a withdrawal. McCain and other Republicans have emphasized the importance of considering conditions on the ground and have argued it is unwise to set a deadline.

But Lee, who also appeared on “Meet the Press,” said she feared a war without end and hoped the president does not backtrack on the July 2011 date.

“I believe we need to stick with what the president initially said — that’s to say we need to begin to end this in July,” she said.

McCain challenged Obama to publicly declare that the date would depend on conditions on the ground. The Senator said the Afghan people and their leader, President Hamid Karzai, need assurance that they can depend on the United States and that the Taliban should not have the opportunity to simply wait out the U.S. military.

“We have to convince the enemy that we are going to do what’s necessary to succeed,” he said. He cited securing Afghanistan against terrorist bases, establishing government control, gaining support of the people and creating a relatively stable environment as measures of success.

McCain supported Obama in accepting the resignation last week of Army Gen. Stanley McChrystal as the U.S. military commander in Afghanistan, following critical statements the general and his staff made to Rolling Stone magazine. He also praised Army Gen. David Petraeus, the chief of U.S. Central Command and the president’s nominee to replace McChrystal.

Petraeus “can bring this to a successful conclusion,” McCain said.