NEW DELHI – Indian Prime Minister Manmohan Singh on Friday ruled out serving another term after an election due by May and threw his support behind Nehru-Gandhi dynasty scion Rahul Gandhi to lead the country if their party wins the vote.

Singh, 81, has presided over India for a decade at the head of coalition governments led by the Congress party and was widely expected to step down.

Gandhi will have his work cut out if he's chosen to lead the Congress party into the election with corruption scandals, stubborn inflation and decade-low growth eroding support, opinion polls show.

"In a few months' time, after the general election, I will hand the baton over to a new prime minister," Singh said at a rare news conference, adding that a "new generation" would guide the country.

Singh said Gandhi, 43, should be the Congress party's prime ministerial candidate.

"Rahul Gandhi has outstanding credentials to be nominated as the candidate and I hope our party will take that decision at an appropriate time."

The Congress is due to hold a top-level meeting on Jan. 17 and is expected to announce its candidate soon afterwards.

Whoever gets the nod will face off in the election against Narendra Modi, of the Hindu nationalist Bharatiya Janata Party (BJP), who is ahead in the opinion polls.

Modi is campaigning on a platform to revive an economy growing at its slowest in a decade and end the red tape and corruption that have bedevilled the Congress-led coalition.

The Congress fared badly in elections in four large states towards the end of last year, largely due to voters' anger over corruption.

"Disastrous"

Compared with the relatively untested Gandhi, Modi has years of experience as the chief minister of the western state of Gujarat where he has built a reputation as a business-savvy and investor-friendly administrator.

But he has been unable to fully shake off allegations over anti-Muslim riots in Gujarat in 2002 in which at least 1,000 people were killed, most of them Muslims.

Modi denies wrongdoing and a Supreme Court investigation found no evidence to prosecute him.

Singh was scathing about Modi, saying he would be bad for India.

"I sincerely believe that it would be disastrous for the country to have Narendra Modi as the prime minister," said the softly-spoken Singh.

Singh rejected a suggestion that he had been a weak prime minister and again referred to Modi.

"If by strong prime minister you mean that you preside over the mass massacre of innocent citizens in the streets ... I do not believe that sort of strength this country needs. Least of all in its prime minister," Singh said.

BJP spokeswoman Nirmala Sitharaman said on her Twitter account she was "utterly disappointed" with Singh's remarks.

In what was seen as his farewell news conference, the prime minister took a conciliatory tone on a dispute with the United States over the arrest of an Indian diplomat in New York.

Singh said the government was committed to good relations between the two countries.

"There have been recently some hiccups but I sincerely believe that these are temporary aberrations and diplomacy should be given a chance to resolve these issues that have arisen," Singh said.