Putin: USA follows uncontained hyper use of force in international relations

"We are prepared to work together with other countries for a comprehensive peace," he said.

"We are a country within the international system - we do believed that peace and security in our region is a necessity and that the great powers should assist us," Larijani said.

Merkel, whose country holds the rotating EU presidency, emphasized the international community's support for Israel and said there was a unified resolve to prevent Iran from developing nuclear weapons.

"We are determined to prevent the threat posed by an Iranian military nuclear program," she said.

Officials often use the annual Munich Conference on Security Policy, now in its 43rd year, as an opportunity to conduct diplomacy.

Some 3,500 police were on hand to keep some 1,300 protesters in check, officials said. Scattered arrests were reported, but police said there were no major incidents.

Heading into the conference, Larijani said he planned to use the gathering as an opportunity to discuss about Iran's nuclear program - the first talks with Western officials since limited U.N. sanctions were imposed in December.

Larijani was expected to meet with German Foreign Minister Frank-Walter Steinmeier and EU foreign policy chief Javier Solana, the AP reports.

Merkel opened the conference by telling the delegates that one of the major threats facing the world today is global warming, urging a combined effort to combat it.

"Global warming is one of the major medium- to long-term threats that could have a dramatic effect," she said.

"This threat is a global threat: It affects everyone - no one can escape - and it is one we can only tackle together," Merkel said.