Costa Rica asked the United States to remove it from a list of Iraq coalition partners Thursday, after the Constitutional Court ruled that inclusion on the list violated the country's pacifist principles.
Foreign Minister Roberto Tovar said a diplomatic note on the issue had been delivered to the U.S. Embassy in San Jose.
Tom Casey, a State Department spokesman, said Costa Rica's membership in the coalition was an expression of the country's opposition to terrorism, and noted that Costa Rica provided neither troops nor economic assistance for Iraq's reconstruction.
White House Press Secretary Scott McClellan said the United States would be willing to remove Costa Rica from the list, though the White House website still listed the country Thursday evening.
"Every country has to make their own decision about how they want to participate, and in what ways," he said.
President Abel Pacheco said that he agreed only to join countries that were against terrorism and that he would comply with the court's order and ask to have Costa Rica removed from the so-called coalition of the willing list.
"I was just supporting a friend in the fight against terrorism," he said. "Costa Rica was against terrorism, against dictatorships and that was it.
"Afterward, it turned out that there weren't weapons [of mass destruction] and all that, but that happens."
The court ruling, announced late Wednesday, was cheered in the Latin nation, which widely rejected the U.S.-led war in Iraq.
"I think it's great," 23-year-old student Rosario Camacho said. "I was opposed to Costa Rica being on the list because it couldn't support the war."
The action comes amid growing fears of terrorist activity in the region, although the decision appeared to have more to do with Costa Rica's pacifist history.
The country has no army, and Oscar Arias, who served as Costa Rica's president from 1986 to 1990, won the Nobel Peace Prize in 1987 for his work bringing peace to Central America.
International terrorists have posted Internet threats against El Salvador for its continuing military support in Iraq. El Salvador is the only country in the region that still has troops in Iraq.