ARLINGTON, Va. — Republican presidential candidate John McCain met Sunday with Iraq's foreign minister, Hoshyar Zebari.

The two discussed security improvements in Iraq, and spoke about negotiations between the two countries on an agreement to pave the way for the future presence of U.S. military forces in Iraq. Many Iraqis object to the idea of an indefinite U.S. presence in their country.

"It's very important that we not let any of this success slip away," McCain said after the meeting at his campaign office near Washington.

Iraqi officials have raised a number of objections to the proposed agreement. Zebari acknowledged there were "difficulties in negotiations." But during an interview later on CNN's "Late Edition," he predicted an agreement would be reached by the end of July.

Asked whether he would promise indefinite protection to the Iraqi people, McCain said the United States has made progress in Iraq and that the decision to send additional troops has worked. He used the opportunity to criticize Democratic rival Barack Obama's stance on the troop increase.

"The situation on the ground is that we have made enormous success and the surge has worked," McCain said. "Senator Obama was wrong when he said it would fail."

Zebari said he also would speak with Obama while he is in the United States. He did not say when that would be.