Mr Clinton did not directly link the bilateral nuclear agreement between the US and North Korea - aimed at halting the North Korean nuclear power programme - to the release of Chief Warrant Officer Bobby Hall. But senior administration officials say failure by North Korea, which claims the helicopter was on a spying mission, to release him could jeopardise the accord which was signed in October.
Already Republican and Democratic members of Congress are saying that they want the pilot, whose OH-58 Scout helicopter was brought down in a snowstorm on 17 December, to be freed before the US makes a shipment of oil worth $4.7m (£3.1m) to North Korea on 21 January. Also threatened are talks about opening diplomatic offices in Pyongyang and Washington, which were due to start soon.
The White House is hoping that the crisis in relations with North Korea can be defused by Thomas Hubbard, a deputy assistant secretary of state who arrived for talks in Pyongyang yesterday. Mr Clinton said: "Let's give our people there a chance to do their work and see what happens."
The administration wants neither to sound too conciliatory in its dealings with the North Koreans nor to wreck the agreement, which is intended to channel Pyongyang's nuclear programme in a peaceful direction. At the heart of the deal reached in October is the American promise to replace energy lost by North Korea through shutting down its present nuclear reactors. Washington is also talking to Japan and South Korea about raising $4bn with which North Korea can buy reactors which produce little nuclear weapons-grade material.
The State Department spokesman, Michael McCurry, said: "It's hard to imagine these things moving forward if we haven't secured Officer Hall's release."
More militantly, the incoming Republican Senate leader, Bob Dole, said: "We may have to block it [the agreement] in any event. This would be another reason to do it. You can't trust the North Koreans."
There is no consensus in Washington about North Korea's motives in refusing to give up the American pilot, though presumably Pyongyang wants to use the incident as a lever in coming negotiations.
In particular it may want to broaden diplomatic links with the US rather than dealing through the Military Alliance Commission, which has handled truce violations since the end of the Korean war.