Russia's foreign minister complained that the North Korea crisis is causing Japan and South Korea to more heavily arm themselves.

South Korea and Japan have expressed interest in getting more US missile defenses.

Russia fears that with a global network of missile defenses, the US could one day launch a nuclear attack on Russia that Russia could not retaliate against.

MOSCOW (Reuters) - Russia is concerned that Japan is allowing Washington to use its territory as a base for a U.S. military build-up in north Asia under the pretext of countering North Korea, Russian Foreign Minister Sergei Lavrov said on Friday.

"We are expressing deep concern, with facts to back it up, that Japan along with South Korea is becoming a territory for the deployment of elements of the U.S. global missile defense system which is being rolled out in that region under the pretext of the North Korea threat," Lavrov said.

"We have no problems directly with Japan, we do not see risks there. We see risks because of the proliferation of a global U.S. missile defense system on the territory of countries that neighbor Russia, including Japan."

Lavrov was speaking at a joint press conference with his Japanese counterpart, Taro Kono, after talks between the two men in Moscow.

"We are alarmed that in the last two months when North Korea conducted no tests or rocket launches, it seemed that Washington was not happy about that, and tried to do things that would irritate and provoke Pyongyang," Lavrov said.

He mentioned that in that period the United States had been conducting military exercises in the region, and had adopted additional sanctions against Pyongyang.

Referring to U.S. officials, he said: "It's as if they are hoping that they (the North Koreans) will lash out again, and then it would be possible to engage in military options."

"As you know, the U.S. leadership has said many times that all options are on the table, including military options, and we note that Japanese Prime Minister Shinzo Abe, at a meeting with President Trump in early November, said that he supports the American position 100 percent," Lavrov said.

Faced with North Korean missile tests, and threats from Pyongyang, Japan is considering buying the U.S.-designed Aegis Ashore missile defense system, according to government sources in Japan.

Lavrov said Moscow was especially concerned that the Aegis Ashore system could be adapted to fire Tomahawk missiles. He said that would be in violation of a U.S.-Russian arms control treaty.

Washington and its regional allies deny they are seeking a military build-up, saying that they are taking the minimum steps necessary to protect themselves from possible aggressive acts by North Korea.