20 March 2017
The US this month began installing the THAAD anti-missile system in South Korea in response to the North's intensifying ballistic missile development.
Allies Washington and Seoul say it is for purely defensive purposes. China fears it could undermine its own nuclear deterrent and has lashed out, imposing measures seen as economic retaliation on South Korea.
Russia, meanwhile, took advantage of diplomatic and defence talks with US ally Japan to criticise the development.
"We drew attention to the serious risks posed by the deployment of elements of the American global anti-missile system in the Asia-Pacific region," Foreign Minister Sergei Lavrov told a press conference, saying Moscow raised the issue in the talks.
"If this is meant to counter threats coming from North Korea, then the deployment of this system and accumulating armaments in the region is a disproportionate reply," he added, apparently referring to THAAD.
Russia last year also expressed worries over plans for the deployment in South Korea.
Lavrov's comments came after so-called two-plus-two talks between the foreign and defence ministers of Russia and Japan.
They also followed a high-profile visit to the region by US Secretary of State Rex Tillerson, who warned that American military action against the North was an option "on the table."
North Korea did come in for criticism at the Russia-Japan meeting for its nuclear and missile development.
"We shared the view that we will strongly urge North Korea to exercise self-restraint over further provocative actions and follow UN Security Council resolutions," said Japanese Foreign Minister Fumio Kishida.
North Korea is banned by the international community from pursuing nuclear and missile programmes but has defiantly ploughed ahead.
It staged its two latest nuclear tests last year and recently fired off missiles which it described as practice for an attack on US bases in Japan.
Japan and Russia also tried to further bridge differences over a long-standing territorial dispute dating from World War II but achieved no major breakthroughs.
The Soviet Union seized four islands off Japan's northern coast in 1945 in the closing days of the war and the dispute has prevented a peace treaty to formally end the conflict.
The foreign and defence ministers' meeting, the first since late 2013, followed a December summit between Japanese Prime Minister Shinzo Abe and Russian President Vladimir Putin that focused on the territorial row.
Kishida announced that Abe will visit Russia in late April to continue
their discussions on efforts to finally conclude a peace treaty ending the