MOSCOW — Russia and China expressed serious concern Wednesday about tension on the Korean peninsula and, in the face of increasingly belligerent rhetoric, joined international pressure for North Korea to return to nuclear talks.
The U.S. vowed it would never accept North Korea as an atomic weapons state and, at a board meeting of the International Atomic Energy Agency in Vienna, urged the country to negotiate with the world's great powers instead of making threats.
Only hours earlier, North Korea warned the United States and its allies of a "thousand-fold" military retaliation if provoked.
Japanese and South Korean news reports said North Korea is preparing an additional site for test-firing a long-range missile that experts say could be capable of striking the United States. A Russian deputy defense minister said earlier that Russia would shoot down any North Korean missile headed its way but might not be able to detect missiles aimed in other directions.
North Korea, which held its first nuclear test in 2006, conducted its second on May 25 in defiance of the United Nations.
China and Russia have in the past used their status as veto-wielding permanent U.N. Security Council members to soften Western-backed sanctions against North Korea, but approved new punitive measures this month after expressing unusually strong concern over North Korea's recent nuclear test and missile launches.
Chinese President Hu Jintao and Russia's Dmitry Medvedev tried to nudge North Korea back in line while taking care to avoid angering it further. Both nations have far warmer ties with North Korea than do the United States or Japan, and Russia has repeatedly warned that pressuring North Korea too hard would be counterproductive.
Pyongyang, which is believed to have enough weaponized plutonium for at least half a dozen atomic bombs, claims they are a deterrence against the United States and accuses Washington of plotting with South Korea to topple its secretive regime.