Russia's foreign ministry said on Wednesday that if the United States stationed missiles in Japan than it would pose a threat to Russia and Moscow would have to take retaliatory steps.
Ministry spokeswoman Maria Zakharova suggested that Russia's nuclear doctrine be consulted to give a guide on what retaliatory steps could be taken in such a situation.
Zakharova said that the United States continued to escalate the situation around Taiwan, undermining regional stability.
She said that the United States had deployed medium-range missiles in the Philippines, a step she said would stoke an arms race and increase strategic risks.