North Korea handed detailed nuclear weapons records to the United States, an important peek into the isolated regime's bombmaking past but not enough to answer criticism that the Bush administration is grasping for a disarmament deal at any cost.
The technical logs from North Korea's shuttered plutonium reactor would give outside experts a yardstick to measure whether the North is telling the truth about a bomb programme that the poor nation has agreed to trade away for economic and political rewards.
"Our top three priorities are going to be verification, verification, verification," said State Department spokesman Sean McCormack.
A US diplomat collected the eight boxes of records during a three-day visit to Pyongyang. McCormack said getting the papers was the main reason for the trip.
Privately, State Department officials hope the approximately 18,000 secret papers will build confidence among conservative critics of the recent, relatively flexible US posture toward North Korea, an isolated dictatorship President George W Bush once termed part of an "axis of evil."
The Bush administration's comprehensive 2007 disarmament deal with the North requires some congressional approval, and Republican unease is growing.
The North is five months past a deadline to produce a complete record of its weapons programmes or an alleged side business selling nuclear know-how to other countries, and US officials announced no new deadline for the summary.
The North claims it met its obligations, but has also agreed to a new tentative deal to break the impasse. That deal would have the North acknowledge US concerns about an illicit uranium programme and alleged sale or transfer of nuclear know-how to other nations but would not require the North to spell everything out.