TAIPEI- Taiwanese President Tsai Ing-wen left for a trip to the United States and the Caribbean on Thursday, warning that democracy must be defended and Taiwan faced threats from “overseas forces”, in a veiled reference to mainland China.

Beijing, which claims the self-ruled and democratic Taiwan as its own and views the island as a wayward province, has called on the US not to allow Tsai to transit there on her overseas tour.

Tsai’s time in the US will be unusually long, as normally she spends just a night at a time on transit stops.

She is spending four nights there in total, two nights on her way to visit four Caribbean allies and two nights on the way back. Tsai will go to New York on her way there, and then is expected to stop in Denver on the way back.

The US State Department has said there has been no change in the US’ one-China policy, under which Washington officially recognises Beijing and not Taipei, while assisting Taiwan.

Speaking at Taipei’s main international airport at Taoyuan, Tsai said she would share the values of freedom and transparency with Taiwan’s allies, and was looking forward to finding more international space for Taiwan.

“Our democracy has not come easily, and is now facing threats and infiltration from overseas forces,” Tsai said, without naming any such force.

“These challenges are also common challenges faced by democracies all over the world. We will work with countries with similar ideas to ensure the stability of the democratic system.”

Tsai, who faces re-election in January, has repeatedly called for international support to defend Taiwan’s democracy in the face of the mainland’s threats.

Beijing has regularly sent military aircraft and ships to circle Taiwan on drills in the past few years.

Tsai last went to the United States in March, stopping over in Hawaii at the end of a Pacific tour.

Seeking to bolster Taiwan’s defences, the US this week approved an arms sale  worth an estimated US$2.2 billion to Taiwan, despite Beijing’s criticism of the deal.

Taipei has been trying to shore up its diplomatic alliances amid pressure from mainland China, which has been whittling down its few remaining diplomatic allies, especially in the Caribbean and Latin America.

Aside from the United States, Tsai will be visiting St Vincent and the Grenadines, St Lucia, St Kitts and Nevis, and Haiti.

Taipei now has formal ties with only 17 countries, almost all small nations in Central America and the Pacific.