There has been a mixed response inside South Korea to news that a vessel thought to be North Korean has been intercepted in the Arabian Sea found to be carrying hidden Scud missiles.
The South Korean authorities say they are still monitoring developments and will not comment until all the facts are confirmed.
But the seizure is likely to have political ramifications coming just a week before the country's presidential elections.
Some analysts say the US may be seeking to influence the outcome of the election in favour of an opposition candidate, whose views on North Korea are more in tune with those in Washington.
Scepticism
Security officials from the US and South Korea held talks for more than three hours to discuss the latest developments.
But when they broke up, no further details were given.
Washington has said the interception of the ship is further evidence that North Korea is a major proliferator of weapons.
The regime is thought to earn between $500m and $600m a year from exports of ballistic missile-related equipment and technology.
But many South Koreans are sceptical, rather than surprised, about the latest developments, coming just a week before the country votes for a new president.
There have been suggestions the US may be seeking to influence the outcome.
Some experts say the US may be favouring the candidate of the opposition Grand National Party, Lee Hoi Chang, whose views on Pyongyang are more in tune with those in Washington.
His rival, Roh Moo Hyun, favours continued engagement with the North.
But he has now urged the regime to stop exporting missiles and join other countries in preventing the proliferation of weapons of mass destruction.
Ironically, as news of the ship seizure broke, a delegation of officials from North Korea arrived in the South for three days of talks on joint economic projects.