LUXEMBOURG (AP) -- Iran's foreign minister dropped in on a meeting of his EU counterparts on Monday, predicting intense and difficult days ahead before a June 30 deadline to strike a deal with world powers over Tehran's nuclear program.

Iranian Foreign Minister Mohamad Javad Zarif held private talks with counterparts from Germany and France, before meeting with a group of EU leaders on the sidelines of a meeting of top EU diplomats in Luxembourg.

"We discussed how we can expedite the discussions in Vienna for the next few difficult days that we have ahead of us," Zarif told reporters after his meetings.

Zarif said political directors will continue drafting an agreement and ministers will be called in "as necessary" to push the process along.

"It's going to be a very intense few days in the next - I don't know how many days it will take to finish this," Zarif said.

Zarif said he believes that if the political will exists among the parties, there is a "good possibility" that a deal could be reached "by the deadline or a few days after the deadline."

Speaking earlier to Iranian state TV, Zarif said all sides in the nuclear talks should avoid "excessive" demands, and noted differences on both technical and political issues.

British Foreign Secretary Philip Hammond, who also met with Zarif, said diplomats are "going to pull all the stops out" to reach an agreement by the deadline. "We're making progress at the official level. At some point later on this week, over the weekend or early next week ministers will need to gather and get involved."

Foreign Minister Laurent Fabius of France, which has been one of the most cautious countries about a possible deal, said his country wanted an accord, but a "robust" one that limits Iran's nuclear research and production capabilities over the long term.

France also favors "an extensive regime of verification, including if necessary military sites" and "an automatic return to sanctions in case Iran violates its commitments," Fabius said in a brief statement after his hour-long meeting with Zarif.

Iran and six nations - the U.S., Russia, China and EU members Britain, France and Germany - are facing the self-imposed deadline in talks aimed to place curbs on Iran's nuclear program in return for the lifting of economic sanctions.

By The Associated Press