By Deutsche Presse-Agentur
Spokesman Josh Earnest dismissed concerns that the US was ratcheting up sabre-rattling on the Korean peninsula, noting: "It's clear that the escalation is taking place from the North Koreans based on their rhetoric and on their actions."
Russian Foreign Minister Sergei Lavrov earlier Friday warned against sabre-rattling on the Korean peninsula, saying that the tensions between North Korea and South Korea could get out of hand.
"It is necessary not to build up military muscles," Lavrov was quoted as saying by the Itar-Tass news agency, in reference to the Korean peninsula.
The situation with North Korea should not be used "as a pretext to solve geopolitical problems by military means, but to concentrate efforts to create conditions for the resumption of the six-nation talks," he said.
"We may just lose control of the situation. It is sliding into a spiral of a vicious circle," Lavrov added.
Earnest however pointed to international "unanimity of opinion across the globe" on North Korea, and noted the US was "coordinating pretty closely with not just our allies, but also with Russia and China that also have a significant stake in resolving this situation peacefully."
Earnest called on North Korea to live up to its international obligations and said the US remained committed to protecting itself and its allies in the region.
"The United States has the capability, and we have demonstrated the willingness to use that capability to protect our interests and our allies," he said. "There's no reason that it should come to that."
The statements came after North Korea earlier in the day issued a new threat to attack the United States in reaction to a show of force by two US B-2 stealth bombers that dropped dummy bombs onto a South Korean training ground.
North Korean leader Kim Jong Un ordered strategic missiles to be prepared "so that they may strike any time the US mainland, its military bases in the operational theatres in the Pacific, including Hawaii and Guam, and those in South Korea," state-run Korean Central News Agency (KCNA) said in an English-language statement.
The US bombers participated in a "long-duration, round-trip training mission" of more than 20,000 kilometres from their US base to South Korea Thursday, the US military in Seoul said.
Relations with Pyongyang have deteriorated since North Korea's third nuclear test in February and the strengthening of international sanctions against it.