Costa Rican President Oscar Arias is suffering from the H1N1 virus, making him the first head of state known to have contracted swine flu.

Nobel Peace Prize winner Arias, 68, has a mild case of the virus which he tested positive for on Tuesday after feeling unwell at the weekend, the government said.

Arias is at home and plans to do some work from there.

"Apart from the fever and a soar throat, I feel well and in good shape to carry out my work by telecommuting. I expect to return to all my duties on Monday," he said in a statement.

The H1N1 flu outbreak, declared a pandemic on June 11, has spread around the world since emerging in April and could eventually affect 2 billion people, according to estimates by the U.N. World Health Organization. More than 20 people have died of swine flu in Costa Rica.

Arias suffers from asthma. While the vast majority of swine flu cases have not been serious, infected people who have other medical conditions are most susceptible to complications.

"The tests ... show that there is no other complication," Information Minister Mayi Antillon said.

Some of the president's duties have been given to Cabinet ministers for the moment.

Last month, Arias brokered talks to try to end a political crisis in Honduras after President Manuel Zelaya was ousted in a coup on June 28.

Negotiations broke down two weeks ago over whether Zelaya can return to power and Arias' illness is unlikely to affect the situation in Honduras.

Arias won the Nobel prize in 1987 for a peace plan to end Central American civil wars and guerrilla conflicts.

He first served as president from 1986-90 and was re-elected in 2006 on a promise to end corruption and take the small country into a Central American free trade pact with the United States.

Arias broke Costa Rica's decades-old diplomatic relations with Taiwan in 2007 to establish ties with rival Beijing, saying his country could no longer ignore China's growing power in the world.

Doctors ordered Arias last year to stop talking for a month due to a vocal chord ailment. He communicated by writing and typing.