By Gopal Sharma

KATHMANDU (Reuters) -A Ukrainian man who lives in the United States said on Friday that he had completed a journey from sea level in New York to the summit of Mount Everest in a record four days, saving weeks that mountaineers usually need to get used to high altitudes.

Climbers to the world's highest mountain normally spend up to two months at different high camps to allow their bodies to adjust to the thin air before ascending to the 8,849-metre (29,032-foot) peak.

The claim could not be verified independently as there is no authority in Nepal to verify the claims of records by climbers. However, usually when mountaineers claim a record it is acknowledged or contested by other climbers or mountaineering bodies that specialise in climbing-related information. Such verification often takes some weeks or months.

On Wednesday, four British climbers who had inhaled Xenon gas in Germany before embarking on the expedition from London, completed their ascent from London to the summit in less than five days. The feat was also not independently verified.

Andrew Ushakov, a structural engineer who is relatively unknown as a climber, said he did not use Xenon gas. He said he embarked on his expedition from New York and scaled the Everest summit on Monday in slightly less than four days.

Similarly to the Britons, Ushakov slept at home in a hypoxic tent that simulates high-altitude conditions before heading to Nepal, and used supplemental oxygen like other climbers.

Ushakov, 40, told Reuters in Kathmandu that he hoped his feat, which came after two years of preparation and research, would set an example for his 6-year-old son to do "something big" in the future and encourage people to take to mountaineering without having to leave work and family for long.

Ushakov said that in an attempt to make a fast ascent of Everest last year, he reached 8,500 m (27,880 ft) but developed a vision problem and failed to complete the climb. He said he broke his arm in Ecuador two months ago when he was hit by an avalanche.

Nepal, home to eight of the world's 14 highest mountains, has issued permits to 468 people to climb Mount Everest during the current season ending this month. About 300 climbers, including the Sherpa guides, have scaled the summit so far.

(Reporting by Gopal SharmaEditing by Sudipto Ganguly and Frances Kerry)