MUMBAI (AFP) - China's premier paid tribute to an Indian doctor who died treating Chinese troops more than 70 years ago, becoming a rare symbol of friendship between the two nations.

Mr Li Keqiang, like Chinese leaders before him, took time out of his hectic India visit to meet relatives of Dwarkanath Kotnis, who provided medical aid for four years during the Sino-Japanese war of 1937-1945.

"The Chinese people will never forget Dr Kotnis," Mr Li told business leaders in a speech in India's financial hub Mumbai after meeting the family.

He called the doctor "a household name" in China for extending valuable medical help to the Chinese "in their most difficult hour".

"With his two hands, he saved the lives of many soldiers in China who fought against Japanese aggression but sadly he lost his life and he gave his life in China," Mr Li said, praising Dr Kotnis as a "Chinese warrior".

Ms Manorama Kotnis, one of the doctor's seven siblings and the only one still alive, met the Chinese premier at the Taj Mahal Palace hotel in Mumbai, along with four of her younger relatives.

"I'm very proud and happy that such a big (personality) still remembers my brother," the 92-year-old told AFP on Monday at her home in Mumbai's Vile Parle suburb, where old pictures of her legendary brother sit proudly on display.

"He was really courageous and he wanted to go out and help people," she said.

While ties between Beijing and New Delhi have often been strained, with a legacy of distrust from a border war in 1962, Kotnis has remained a widely revered figure in China for his war work.

Born in western Maharashtra state, of which Mumbai is the capital, he was one of five medical volunteers dispatched from India in 1938, following a request for help from the fellow Asian giant.

Ms Manorama, who was a teenager when her older brother left, said the team was only supposed to go for a year.

But her brother stayed on for four years, joining the Chinese Communist Party and marrying a Chinese nurse, with whom he had a son a few months before he died of epilepsy in 1942, aged 32.

Mr Manorama, a former nutritionist, said he struggled with the workload and the lack of proper food on the frontline, where he was required at times to operate continuously for 72-hour stretches.

The Indian family kept in touch with his widow Guo Qinglan, who died last year and whose portrait also sits in the apartment, along with ornamental Chinese gifts from their high-profile visitors over the years.

Former Chinese premier Hu Jintao met the family in Mumbai in 2006 and they gave him a copy of the Bollywood film "Dr Kotnis Ki Amar Kahani" (The Immortal Story of Dr Kotnis). A Chinese movie has also documented his life.

Mr Li met the family on his second and final day in India, which marked his first foreign visit since taking office in March.

Mr Li and India's Prime Minister Manmohan Singh pledged on Monday to resolve a border dispute that has soured ties for decades, saying good relations between the two Asian giants were key to world peace.

It was a sentiment shared by Ms Manorama, who expressed sadness that the two countries had failed to forge closer links in the decades since her brother lost his life.

"They should come together, live in peace, help each other," she said.