Both Halonen and Swedish Prime Minister Fredrik Reinfeldt are visiting the United States for the Annual Gala Dinner of the American Scandinavian Foundation. Reinfeldt's request for a meeting with Bush was approved, and the men met Tuesday.
A statement from Halonen's office said scheduling problems are routinely invoked in international diplomacy, the Helsingen Sanomat reported.
Reinfeldt arrived in the United States on Sunday, while Halonen wasn't scheduled to arrive until Wednesday.
Reinfeldt, a conservative, told reporters the main theme of his meeting with Bush was climate policy, which he said he will also discuss with California Gov. Arnold Schwarzenegger on Wednesday.
After the meeting, Bush and reinfeldt told reporters they also discussed international trade.
Both Nordic leaders scheduled meetings this week with U.N. Secretary-General Ban Ki Moon in New York, the report said.