U.S. President Barack Obama and his South Korean counterpart Park Geun Hye pledged to stand firm together against North Korea's provocations and security threats, with Obama reaffirming Washington's commitment to defending Seoul.
At a joint press conference following their first meeting at the White House, Obama said, "We are determined to be fully prepared for any challenge or threat to our security and obviously that includes the threat from North Korea."
"The commitment of the United States to the security of the Republic of Korea will never waiver," he said, referring to the South by its official name.
"If Pyongyang thought its recent threats would drive a wedge between South Korea and the United States or somehow garner the North international respect, today is further evidence that North Korea has failed again," Obama said, adding that Washington will continue to coordinate closely with South Korea and Japan.
Noting that North Korea is more isolated than ever amid tightening international sanctions, Obama said, "In short, the days when North Korea could create a crisis and elicit concessions, those days are over."
South Korea's Park also told the press conference, "The president and I reaffirm that we will by no means tolerate North Korea's threats and provocations."
"It is important that we continue to strengthen our deterrence against North Korea's nuclear and conventional weapons threat," she added.
The tough stance expressed by the two leaders may spark strong reaction from North Korea, although the country has recently eased provocations after months of bellicose warnings and suspicious military developments.
Obama said the two countries are prepared to engage with North Korea diplomatically, but he said, "The burden is on Pyongyang to take meaningful steps to abide by its commitments and obligations, particularly the denuclearization of the Korean Peninsula."
He also hailed South Korea's "calm and steady" resolve in dealing with North Korea.
Apparently bearing recent political reform movements in Myanmar, Obama noted that he and Park discussed that "Pyongyang should take notice of events in countries like Burma."
In a joint declaration released after the bilateral summit meeting, the two countries said the U.S.-South Korean alliance which marks the 60th anniversary has served "as an anchor for stability, security and prosperity on the Korean Peninsula."
"The United States remains firmly committed to the defense of the Republic of Korea, including through extended deterrence and the full range of U.S. military capabilities, both conventional and nuclear," the declaration said.
Washington and Seoul also "share the deep concern" that North Korea's nuclear and ballistic missiles program and its repeated provocations pose grave threats to the peace and stability of the Korean Peninsula and Northeast Asia, the declaration said.
Among other bilateral issues, Obama and Park reaffirmed that the two countries are on track for South Korea to assume operational control for the security alliance in 2015.
The two leaders also agreed to continue to enhance economic cooperation.
Park, the first female leader in North East Asia, is scheduled to deliver a speech before the U.S. Congress on Wednesday.