Russian President Vladimir Putin warned Saturday that the United States' increased use of military force is creating a new arms race, with smaller nations turning toward developing nuclear weapons.
Speaking at a conference of the world's top security officials, including Iranian nuclear negotiator Ali Larijani, Putin said nations "are witnessing an almost uncontained hyper use of force in international relations."
"One state, the United States, has overstepped its national borders in every way," he told the 250 officials, including more than 40 defense and foreign ministers.
"This is very dangerous: Nobody feels secure anymore because nobody can hide behind international law," he said through a translator.
"This is nourishing an arms race with the desire of countries to get nuclear weapons," he added, without singling out any particular nation.
In a harshly critical speech, Putin also voiced concern about U.S. plans to build a missile defense system in eastern Europe, probably Poland and the Czech Republic, and the expansion of NATO as possible challenges to Russia.
"The process of NATO expansion has nothing to do with modernization of the alliance or with ensuring security in Europe," Putin said. "On the contrary, it is a serious factor provoking reduction of mutual trust."
NATO Secretary General Jaap de Hoop Scheffer responded by saying he saw a "disconnect" between the West's growing partnership with Russia and Putin's statements.
"I can't hide my disappointment" with Putin's remarks, he said. "Who can be worried that democracy and the rule of law is coming closer to their borders?"
In his speech, Putin also dismissed suggestions that the European Union and NATO had the right to intervene alone in crisis regions.
"The legitimate use of force can only done by the United Nations, it cannot be replaced by EU or NATO," he said.
On the missile defense system, Putin said: "I don't want to accuse anyone of being aggressive" but suggested it would seriously change the balance of power and could provoke an unspecified response.
"That balance will be upset completely and one side will have a feeling of complete security and given a free hand in local, and probably in global, conflicts," he said. "We need to respond to this."
U.S. Defense Secretary Robert Gates had little to say about the accusations, remarking only that Putin "was very candid."
U.S. presidential hopeful Senator John McCain challenged Putin's statements, saying it was not a matter of U.S. hegemony.
"The United States did not single-handedly win the Cold War in some unilateral victory - the trans-Atlantic alliance won the Cold War," he said, adding that "the Russian leader's apparent belief to the contrary" raises some questions.
"Will Russia's autocratic turn become more pronounced, its foreign policy more opposed to the principles of the western democracies and its energy policy used as a tool of intimidation?" McCain asked. "Or will it build, in partnership with the West, a democratic country that contributes to the international rules-based system?"
Putin's spokesman Dimitry Peskov said the Russian leader did not intend to be confrontational, but acknowledged it was his harshest criticism of the United States since he was elected in March 2000.
"The reason for his comments is Russia's concern about the growing amount of conflicts and the malfunctioning of international law," Peskov told The AP.
"Until we get rid of unilateralism in international affairs, until we exclude the possibility of imposing one country's views on others, we will not have stability."
Kurt Beck, chairman of German Chancellor Angela Merkel's coalition partner Social Democrats, called Putin's speech "impressively candid."
"You saw a candidness which is a symbol that there is a readiness to talk about the problems, to have an exchange on the basis of honesty," Beck said.
Earlier, Merkel said Iran needs to accept demands made by the U.N. and the International Atomic Energy Agency on its nuclear program.
"There is no way around this," Merkel said. "What we are talking about here is a very, very sensitive technology, and for that reason we need a high degree of transparency - which Iran has failed to provide - and if Iran does not do so, then the alternative for Iran is to slip further into isolation."
Putin also pushed for an Iranian response.
"I think together we should be patient and work to provide incentives to show the Iranian leadership that cooperation is much better than confrontation with the international community," he said.
On the sidelines of the conference, Larijani defended his country's nuclear program as peaceful, saying: "We are no threat to our region or other countries," while indicating a willingness to return to negotiations.
"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.