Taiwan must rely on itself for its security, the island's foreign ministry said Tuesday, responding to President Donald Trump saying Chinese President Xi Jinping told him he would not invade the island while Trump was in office.

Democratic Taiwan has over the past five years or so faced ramped up military and political pressure from China, which views the separately governed island as its "sacred" territory. Beijing has never renounced the use of force to bring Taiwan under its control.

Asked about Trump's remarks, Taiwan Foreign Ministry spokesperson Hsiao Kuang-wei said the government closely monitored interactions between senior U.S. and Chinese officials.

"Taiwan's security must be achieved through its own efforts, so our country has been dedicating itself to raising its self defense capabilities and resilience. Our country will keep working hard to do this," Hsiao told reporters in Taipei.

The United States is Taiwan's most important international backer and arms supplier, although there are no formal diplomatic ties. There is also no defense treaty so should China attack Washington is under no obligation to help.

The United States, which is however bound by law to provide Taiwan with the means to defend itself, has long stuck to a policy of "strategic ambiguity," not making clear whether it would respond militarily to a Chinese attack on Taiwan.

Trump made the invasion comments in an interview with Fox News, ahead of talks in Alaska with Russian President Vladimir Putin over Moscow's war in Ukraine.

China's foreign ministry said Monday that Taiwan was an internal matter that was for the Chinese people to resolve.

Taiwan's government vehemently opposes China's sovereignty claims.