TAIPEI: Taiwan says President Tsai Ing-wen will visit allies Panama and Paraguay next month on her first overseas trip since taking office, amid speculation over possible moves by China to tighten its diplomatic noose around the self-governing island.

Tsai's trip will likely include the usual stop-overs in the US, although arrangements are still being made, Foreign Minister David Lee told legislators in the capital Taipei.

Lee said Tsai would attend the formal opening the expanded Panama Canal next month, an event to which Beijing is also expected to send a representative.

China has formal diplomatic relations with just 22 nations as a result of China's efforts to isolate the island it claims as its own territory. Most allies are in Central America, the Caribbean, Africa and the South Pacific.

Some observers expect China to further reduce Taiwan's diplomatic breathing space in order to put pressure on Tsai, who since her inauguration last week has refused to explicitly endorse Beijing's stance that Taiwan is part of China and whose Democratic Progressive Party advocates the island's formal independence.

A renewed effort to win away Taiwan's remaining allies would be a key indication that China plans to get tough on her administration. China in March established formal diplomatic ties with the small African nation of Gambia, which had severed relations with Taiwan in 2013, in what was seen as a move toward abandoning the unspoken diplomatic truce between the sides that lasted for eight years under Tsai's China-friendly predecessor.

However, China has made no move to block Taiwan's participation in this week's World Health Assembly in Geneva, run by the United Nations, from which Taiwan is excluded.

Taiwan's health minister delivered a letter of protest to World Health Organisation Director-General Margaret Chan stating that Taiwan's participation in the annual gathering should not be contingent on it accepting Beijing's "one-China principle."