(Corrects physician's name in paragraph 3)
KATHMANDU, June 27 (Reuters) - Nepal's Prime Minister Sushil Koirala will undergo a course of radiotherapy in New York after being diagnosed with lung cancer, his aide, Dinesh Bhattarai, said on Friday.
Koirala, 75, a heavy smoker, has been undergoing medical tests at New York's Memorial Sloan Kettering Cancer Centre for the past two weeks.
The doctors have recommended a course of radiotherapy for Koirala, who also suffers from chronic bronchitis, his personal physician Karbir Nath Yogi told domestic media from New York.
"But we can take comfort that it is in an initial stage," Yogi told the Kathmandu Post daily.
Koirala has been receiving treatment for tongue cancer at the same hospital for more than seven years.
He has been heading a centre-left coalition since February after the November election produced a hung parliament, with his centrist Nepali Congress party emerging as the biggest group.
Nepal, wedged between India and China, has had six governments since the abolition of its centuries-old monarchy in 2008.
A specially elected constituent assembly is struggling to prepare the first post-monarchy constitution, which is expected to bring stability to the impoverished nation, still emerging from a decade-long civil war that has killed thousands. (Reporting by Gopal Sharma; Editing by Malini Menon and Clarence Fernandez)