South Korea has downplayed the North’s stepped - up war rhetoric, saying its nuclear neighbor is not ready for an all - out war with the US - backed South.“To wage an all-out war, they need huge amount of military supplies as well as military force and armament to carry on,” South Korea's Defense Ministry spokesman Kim Min-Seok said at a news briefing on Friday. Regarding various aspects, “they will surely be defeated if they conduct an all-out war against the combined military forces of the United States and South Korea,” he stated. Meanwhile, top South Korean officials have met with Japanese and Chinese ambassadors to discuss ways of restoring peace and stability on the Korean Peninsula. Prior to this, the North had demanded an immediate halt to the US-South Korean military drills in the region and the withdrawal of UN sanctions against the country, demands dismissed by both Seoul and Washington. The refusal prompted Pyongyang to give South Korea an "ultimatum" to end its hostile policies and warned that North Korea would not give any advance notice before attacking the South. Tensions on the Korean Peninsula heightened last month after the US deployed its nuclear-capable B-52s and B-2 stealth bombers to the region as part of its joint war game with the South. Pyongyang stepped up its war rhetoric in response to the “provocative” move, and threatened to launch a preemptive nuclear strike against the US and its regional allies. North Korea has also said its military should be prepared to attack “all US military bases in the Asia-Pacific region, including the US mainland, Hawaii, and Guam,” in addition to South Korea. On April 12, South Korea raised doubts over its neighbor's military nuclear capability, saying it was unlikely that North Korea had managed to make a small, light warhead that could be mounted on a missile.