As President Obama arrives in Seoul on Sunday to join world leaders at a nuclear security summit, his hopes of demonstrating international progress toward keeping fissile materials away from terrorists will be superceded by the more urgent nuclear standoff with North Korea.
Obama is scheduled to open the three-day trip by making his first visit to the demilitarized zone that divides the Korean peninsula, where he will have a chance to reaffirm the US alliance with the South at a time of renewed saber-rattling from Pyongyang.
White House aides said the president will use the occasion to thank the 28,500 US troops stationed in the South for their service.
But Obama's remarks are expected to kick off an intensive administration lobbying effort to ramp up international pressure on the North to scuttle plans to launch a long-range rocket in mid-April.
Administration officials have condemned the plan as a 'direct violation' of Pyongyang's recent promise to halt weapons tests in exchange for food.
In a series of bilateral meetings, Obama will press the leaders of China, South Korea and Russia to "bring all the instruments of power to bear to influence the decision-making in North Korea," said Danny Russel, senior director for Asia at the National Security Council.
Obama will consult with his counterparts about "what we can do to help ensure that North Korea doesn't make the wrong choice . . . " Russel added.
(In exclusive partnership with The Washington Post)