East Timor's president is considering taking the UN's top human rights job but must consider whether his early departure would disrupt his country's fragile peace.

Jose Ramos Horta told reporters he had a strong sense of duty to the young nation and was torn between that responsibility and taking the job of UN High Commissioner for Human Rights.

"I can't say anything yet. I'm waiting 24 hours to say whether I'm a candidate or not because of my concern and responsibility to this country," he said. "I'm taking all the consequences into consideration. I've spoken to many people and I promise to announce my decision tomorrow."

Incumbent UN Human Rights Commissioner, judge Louise Arbour, is due to step down at the end of the month.

Ramos Horta was supposed to make a decision on Thursday about whether he would take the job if it was offered. But after keeping reporters waiting for two hours, he said he needed more time.

If he accepts, it would force an election in East Timor, where the president is directly elected by the people, within 90 days. Major opposition party Fretilin said it would support Ramos Horta if he wanted the UN role.

"Though naturally we would prefer him to continue in his role as the elected president of this country, it is very much a matter for Dr Ramos Horta and Fretilin supports whatever decision he makes," Fretilin spokesman Jose Teixeira said.

The decision to accept is clearly a weighty one for Ramos Horta, who was elected president for a five-year term in a landslide victory just a year ago.

Timor gained full independence only six years ago and stability in the tiny nation is still shaky. Dozens of people were killed and thousands left homeless in civil unrest that swept the country in 2006, when Ramos Horta was foreign affairs minister.

He later stepped up to become prime minister and in 2007 ran for president and won easily, using his term to push for the swift development of his country.

But his term in office was shattered in February this year when rebel soldiers shot him in a failed assassination attempt.

Two months after the shooting, Ramos Horta's office scotched suggestions he would quit. But in an earlier newspaper interview, Ramos Horta said he could not promise to serve out his full term.

Despite Ramos Horta claiming he has broad support for the UN job, including from Australia and the United States, there has been some doubt about the former Nobel Laureate's suitability.

Earlier this month, he gave clemency to a former militia leader convicted of crimes against humanity and former interior minister Rogerio Lobato, who was convicted of arming civilians during the 2006 unrest. But the president has dismissed such concerns.

"I think that is a very narrow minded approach that some people have suggested a head of state should relinquish his prerogative to grant pardons," he said.

Prime Minister Xanana Gusmao, who attended Thursday's press conference, said that as a friend he would support Ramos Horta if he wanted the UN job.