Russian Foreign Minister Sergei Lavrov has warned that an escalation in tensions between North Korea and the United States could get out of control, and urged all sides involved in the standoff to show restraint.
Lavrov's warning came after North Korea announced it has put missile units on standby for strikes on the U.S. mainland and military bases in the Pacific and South Korea.
Lavrov told journalists in Moscow on March 29 that the situation could "spiral" into a crisis.
"We are concerned that, along with the adequate reaction of the UN Security Council and the collective reaction of the world community, there are unilateral actions being taken around North Korea that are increasing military activity," Lavrov said.
"You know, we may simply see the situation get out of control and spiral down into a vicious circle."
North Korean leader Kim Jong Un ordered rockets put on standby late on March 28 in response to U.S. stealth-bomber flights over the Korean Peninsula.
Kim was quoted by a broadcaster on North Korean television as saying that "the time has come to settle accounts with the U.S. imperialists."
In South Korea, the Yonhap news agency quoted an unidentified military source as saying there had "recently" been additional troop and vehicle movements at the North's missile sites, particularly at medium- and long-range missile facilities.
South Korean Defense Ministry spokesman Kim Min-seok maintained that his country and the United States were watching the suspect sites.
"South Korean and U.S. intelligence personnel are closely monitoring North Korea's readiness with regard to its short-, middle-, and long-range missiles such as Scud, Rodong, and Musudan missiles," he said.
U.S. Defense Secretary Chuck Hagel told reporters at the Pentagon on March 28 that the decision to send two nuclear-capable B-2 bombers to join military drills with South Korea was part of normal exercises.
Hagel also maintained that North Korea's provocative actions and rhetoric had "ratcheted up the danger" on the Korean Peninsula and that the United States was prepared for any eventuality from Pyongyang.
"We must make clear that these provocations by the North are taken by us very seriously and we'll respond to that," he said.
Tensions on the peninsula have been high since North Korea's third nuclear test last month, which led to the imposition of new sanctions.
On March 27, Pyongyang said that war "may break out at any moment."
It had previously threatened nuclear strikes on the United States and South Korea and announced it has canceled the armistice that ended the Korean War in 1953.
The country is believed to be years away from developing nuclear-tipped missiles that could strike the United States.
With reporting by AFP, AP, and Reuters