Taiwan's President Ma Ying-jeou made a surprise stopover in Mumbai on his way to Africa in what officials said was a sign of improving ties with India despite a lack of diplomatic recognition.

Ma had kept tight-lipped about the two-hour refuelling stop in India until he departed Taipei late Saturday for his first trip to Africa since he was elected in 2008. The three-leg trip will take Ma to Burkina Faso, Gambia and Swaziland.

"This is a sign of the improving ties with India," foreign ministry spokesman James Chang said, adding that Taiwan planned to open a second liaison office in India, in addition to the one already in New Delhi.

Beijing has opposed any overseas visit by government officials from Taiwan, which it still regards as part of its territory awaiting to be reunified by force if necessary, even though the island has ruled itself for more than 60 years since their split in 1949 at the end of a civil war.

Both sides have previously accused each other of using generous financial packages to ensure the loyalty of governments or persuade them to switch allegiance, especially in Africa, Latin America and the Pacific.

However, ties have improved markedly since Ma of the China-friendly Kuomintang party took office in 2008 and vowed to maintain a "diplomatic truce" with Beijing. Ma was re-elected for a second and last four-year term in January.

Only 23 nations formally recognise Taipei over Beijing.