Hsiao Bi-khim, well-connected in Washington, resigned from the job as US envoy this month to be the running mate for current Vice-President Lai Ching-te in Taiwan’s Jan 13 presidential election. President Tsai Ing-wen cannot run again after two terms in office.

The presidential office said it had appointed Alexander Yui, Taiwan’s representative to the European Union, to replace Hsiao.

The US is Taiwan’s most important international backer and arms supplier even though Washington does not formally recognise its government, maintaining official relations only with Beijing which claims the island as its own territory.

Tsai “hopes to use ambassador Yui’s rich cross-regional diplomatic experience to help promote the continuous deepening of Taiwan-US relations on the existing solid foundation”, the presidential office said.

The government only approved the EU appointment of the trilingual Yui, who also speaks fluent Spanish, in June.

Yui is a former deputy foreign minister and previously ran Taiwan’s office in Geneva.

The statement used the title “ambassador” though it is not formally used, given neither the US nor the EU have official relations with Taiwan.

Yui’s spot in Brussels will be filled by deputy foreign minister Roy Lee, the presidential office said, a rising diplomatic star in Taiwan’s foreign service who received his doctorate from the Australian National University in Canberra.