United States president Barack Obama has called on North Korea to end what he called its belligerent approach amid the current tension in the region.
Speaking after talks with United Nations Secretary-General Ban Ki-moon on Thursday, Mr Obama said no one wants to see a conflict on the Korean peninsular.
South Korea and the US remain on high alert for an expected North Korean missile test launch.
The last month has seen increasingly bellicose rhetoric from the North in response to joint military exercises being carried out by the US and South Korea off the Korean peninsular, the BBC reports.
But with the anniversary of the birth of North Korea's founder Kim Il-Sung coming up, Mr Obama said the US would take "all necessary steps to meet its obligations in the region".
A Pentagon study, made public on Thursday, reveals for the first time that North Korea is believed to have nuclear-armed ballistic missiles at its disposal, although how reliable they are is still in question.
Meanwhile, US Secretary of State John Kerry has arrived in South Korea on Friday for talks about the crisis.
Mr Kerry's trip, which also includes visits to China and Japan, was planned more than a month ago.
In Seoul and Tokyo he will underline America's commitment to defend its allies, while in Beijing he will push for more to be done to rein-in North Korea, the BBC reports.
G8 ministers condemn nuclear programmes
Foreign ministers from the G8 group of nations on Thursday condemned North Korea's nuclear weapons and ballistic missile programmes in the strongest possible terms.
In a news conference after the talks, British Foreign Secretary William Hague said if North Korea conducts another missile launch or nuclear test, the G8 group has committed itself to take further significant measures.
The Group of Eight nations comprises the US, Britain, France, Germany, Italy, Japan, Canada and Russia.
The BBC reports that Japan, which was present at the talks, had been looking for a strong statement of solidarity over Korea.
Mr Hague said the ministers condemned North Korea's "current aggressive rhetoric", saying it would only serve further to isolate the country.
Meanwhile, New Zealand's ambassador in South Korea says despite current tension with the North it's business as usual in the capital, Seoul.
Patrick Rata says the embassy has had some inquiries from New Zealanders anxious about what they are reading and seeing, but there is no specific information to suggest a threat to anyone's safety.
Mr Rata told Radio New Zealand's Morning Report programme just over 1000 New Zealanders are registered on the Government's Safe Travel website as being in South Korea.