BEIJING - The foreign ministers of Russia and China on Friday expressed their joint opposition to the U.S. deployment of an anti-missile system in South Korea and said non-claimants should not take sides in the dispute over the South China Sea.

The comments by Russia's Sergey Lavrov and China's Wang Yi following talks in Beijing display their countries' converging interests and mutual support in foreign affairs as they seek to counter the influence of the U.S. and its allies, particularly in Asia.

Despite endorsing United Nations Security Council sanctions against North Korea over its missile launches and nuclear tests, the two strongly criticized the proposed deployment of the Terminal High-Altitude Area Defence, or THAAD, system.

"Relevant countries shouldn't use Pyongyang's acts as a pretext to increase their military presence on the Korean Peninsula," Lavrov said. "We believe the possible deployment of the THAAD anti-missile system won't resolve this problem."

Both Russia and China, North Korea's now largely estranged ally, see the deployment as exceeding what is necessary to defend against any North Korean threat and would "directly affect strategic security of Russia and China," Wang said.

That could "add fuel to the fire of an already tense situation and even possibly wreck the regional strategic balance," Wang said.

Both called for efforts to restart long-stalled six-nation talks on ending North Korea's nuclear programs.

On the South China Sea, which China claims almost entirely, Lavrov said outside parties shouldn't interfere, a reference to the United States, which has challenged Beijing's claims.

Wang said it was up to those countries directly involved to find a peaceful resolution through negotiations.

"International society, particularly countries from outside the South China Sea, should play a constructive function in maintaining peace and stability and not contribute to the situation becoming more chaotic," Wang said.

Criticized over its aggressive tactics and construction of new islands with airfields, harbours and radar stations, China has sought to use Russia to bulk up its side of the argument against the U.S. and claimants such as the Philippines, which has brought a suit at the UN Court of Arbitration seeking a ruling on ownership over territories it claims.

China has refused to take part in the arbitration or recognize the court's ruling.

Along with enlisting Russia's support, China has given heavy publicity to what it calls a new consensus reached with Brunei, Cambodia and Laos - three members of the 10-country Association of Southeast Asian Nations - endorsing its stance that the South China Sea dispute should not be an issue for ASEAN as a whole.

That has renewed criticisms from some that China is applying divide-and-conquer tactics with its smaller neighbours and trying to drive a wedge through the organization. ASEAN members Brunei, Malaysia, Vietnam and the Philippines contest China's claims, while Taiwan also claims much of the area.