Newly-retired Boris Yeltsin is in excellent spirits and has had the best New Year's celebrations in years, a close aide said on Sunday.

The former Russian leader shocked the world by resigning on New Year's Eve, handing over power to his prime minister, Vladimir Putin.

Kremlin Deputy Chief of Staff Igor Shabdurasulov said Mr Yeltsin's wife, Naina, was also buoyed by his decision to step down. "Naina Iosifovna took the decision with great relief," he said.

Mr Shabdurasulov said that after seeing the New Year in, Boris Yeltsin in an "excellent" mood. "He even said that it was the first time in years he had met the new year in such high spirits," he added.

Mr Yeltsin is currently staying at his old presidential residence, Gorki-9, which is outside Moscow.

The deputy chief of staff said Mr Yeltsin could be expected to stay there for the next three months.

"There is no point rushing to change everything," he said.

Eventually, suitable accommodation would have to be found for the Russian Federation's first ever president, Mr Shabdurasulov said.

He also said Mr Yeltsin would probably continue to be addressed as "president" like his counterparts in the United States.

"We haven't been through this before," he said.

"[But] we should follow the best example of democracy and address a person who occupied the office of president of the Russian Federation with appropriate respect," he said.

Retirement package

Out of office, Boris Yeltsin is entitled to three quarters of his usual salary as well as a dacha, medical insurance, personal staff, a car and bodyguards for himself and his family.

But the most significant of all, says the BBC's Andrew Harding in Moscow, is the complete immunity Mr Yeltsin gets from prosecution.

In the past year, the Kremlin has been at the centre of major corruption scandals, many of which implicate the former president and his family members.

Although Mr Yeltsin's family do not have immunity, it is widely expected that acting Russian President Vladimir Putin will not make life difficult for his predecessor's family.

However, Mr Yeltsin's daughter Tatyana Dyachenko, who was one of his closest advisors, is not expected to hold on to her position.

"I think that Tatyana Borisnova will change her status," Igor Shabdurasulov said.

"I think that's obvious," he added.

Meanwhile, Mr Yeltsin will shortly leave for an Orthodox Christmas pilgrimage to holy sites in Israel and the West Bank.