WASHINGTON (Reuters) - U.S. government officials on temporary duty in Nicaragua were expelled this week, the U.S. State Department said on Thursday, adding the action was "unwarranted and inconsistent with the positive and constructive agenda" it seeks with Managua.

State Department spokesman John Kirby told a news briefing that three officials had only recently arrived in Nicaragua when they were expelled on Tuesday. He did not elaborate on what they were doing in the Central American country.

Nicaragua's government said that in an "unfortunate incident," it removed two U.S. officials from the country who were performing Customs security work tied to anti-terrorism, without the knowledge of local officials.

It was not immediately clear why Nicaragua and the United States had different figures for the number of U.S. officials in the country.

"Such treatment has the potential to negatively impact U.S. and Nicaraguan bilateral relations, particularly trade," Kirby told reporters when asked about the incident. "We've conveyed our strong displeasure," Kirby said, referring specifically to Francisco Campbell, Nicaragua's ambassador to the United States.

In a letter distributed to the press, Campbell said the U.S. officials' anti-terrorism activities "were carried out without the knowledge or the proper coordination with Nicaraguan authorities, which is ... very delicate and sensitive."

Nicaragua said it told the U.S. government "of the necessity to inform (them) about official missions that come to Nicaragua, and to coordinate their work."

Kirby did not say whether Nicaragua's ambassador had been summoned to the State Department or the U.S. sentiments had been conveyed in some other manner.

"We believe it was unwarranted and inconsistent with the positive and constructive agenda that we seek with the government of Nicaragua," he said of the expulsion.

(Reporting by David Alexander, Additional reporting by Ivan Castro in Managua; Editing by Tom Brown and Peter Cooney)