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.
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.
Taiwan's health minister delivered a letter of protest to World Health Organization 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.