Russia is concerned that U.S.-led missile defense initiatives in Europe and Asia are based on an erroneous assessment of the threat posed by Iran, Foreign Minster Sergey Lavrov said Tuesday.

At talks in Tokyo with his Japanese counterpart, Lavrov also acknowledged that a joint U.S.-Japan missile defense pact addressed a legitimate threat from North Korea, but that Moscow was concerned over the global reach of Washington's missile defense network, according to Foreign Ministry official Akira Muto.

"North Korea poses a fundamental threat, but Iran does not," Lavrov was quoted as telling Japanese Foreign Minister Masahiko Komura.

While Moscow "understands Japan's missile defense system is not aimed at Russia," it has concerns over Washington's moves to extend its missile defense network "on a global scale," Lavrov was quoted as saying.

Lavrov's remarks came after U.S. and Russian negotiators ended talks in Moscow Friday over issues that have chilled relations, including a missile defense system the U.S. wants to build in Eastern Europe.

Washington and Moscow disagree over when Iran's missile program would reach a stage where it could threaten all of Europe and the United States. The Russians say that is a far-distant prospect; the Americans say it is coming soon.

Still, U.S. Defense Secretary Robert Gates said Tuesday during a visit to the Czech Republic that Washington could delay activating proposed missile defense sites in Europe until it has "definitive proof" of a missile threat from Iran.

Following their meeting, Komura assured Lavrov that the U.S.-Japan missile defense system posed no dangers for Russia and that Tokyo will push ahead in bolstering cooperation with Washington.

"Our missile defense is not a spear, but a shield. It is an exclusively defense-oriented policy of Japan," Komura told reporters. "We intend to push ahead with our plans together with the United States," he said.

Japan and the U.S. have been jointly developing an advanced missile defense system, and stepped up joint missile defense programs since North Korea's nuclear test last year.

The two countries held a regional ballistic missile defense drill in July, with another round of exercises scheduled for November. The U.S. also keeps about 50,000 troops in Japan under a bilateral security pact.

Lavrov, who is in Tokyo on a one-day visit, also promised following his meeting with Komura to work toward resolving a long-standing territorial dispute over four Russian-held islands also held by Japan.

Tokyo and Moscow will also hold a working level meeting on economic cooperation in Russia's Far East and Siberia on Oct. 26-27 in Vladivostok, the two sides said in a joint statement issued after the talks.

Lavrov was slated to leave Japan Tuesday night for Harbin, China, where he will attend a trilateral ministerial meeting with China and India, according to Japan's Foreign Ministry.