"The countries with diplomatic relations with China can only maintain unofficial business and trade ties with Taiwan," the spokesperson said in a written response to questions. We would urge related countries to abide by the one-China policy and take a cautious approach in handling Taiwan issues."

Issue raised in Canberra

It is understood the issue was raised in Canberra with officials from the Department of Foreign Affairs and Trade.

Beijing still regards Taiwan, a self-governed island of more than 23 million people as a renegade province that will return to the fold some day and few countries are prepared to upset the world's second-biggest economy by challenging its position.

"Australia did send a signal by tweeting that picture about our relationship with Taiwan and our capacity to engage with Taipei both warmly and in a calculation of our national interest," said Mark Harrison, senior lecturer in Chinese Studies at the University of Tasmania.

"Australia has a long-standing effective relationship with Taiwan framed by the one-China policy. It is reasonable for Australia to engage with Taiwan in order to sustain and support the relationship."

The adherence by most countries to the one-China policy has left the Taiwanese government with limited room to move on the world stage. Beijing has resisted Taipei's efforts to join international organisations. China has also pressured companies including Qantas to change the way they refer to "Chinese territories" Taiwan, Hong Kong and Macau, in marketing material.

More unpredictable approach


The politics around Taiwan's international relationships have been heightened since the election in the United States of Donald Trump, who has taken a more unpredictable approach on the issue, unsettling China's Communist Party leaders. After Mr Trump was elected, he controversially broke with protocol to accept a congratulatory phone call from the Taiwanese leader, the first US president or president-elect to do so since at least 1979. He also suggested the one-China policy was up for negotiation, although was forced to backtrack and reaffirm Washington's support after Beijing froze high-level communication.

Beijing has been further riled by the recent appointment of China hawks Mike Pompeo and John Bolton, as Secretary of State and National Security Adviser. It has been suggested Mr Bolton might travel to Taipei next month for the opening of the new US representative office.

The US Congress recently passed the Taiwan Travel Act, which urges high-level visits between the US and Taiwan.

China has also moved actively, since Ms Tsai and her independence-leaning Democratic Progressive Party came to power in 2016, to pick off Taipei's remaining international partners. Beijing has established formal relations with four of Taipei's partners, including the Dominican Republic, Gambia, Sao Tome and Principe and Panama. The diplomatic drive ended a decade-long truce that coincided with warmer cross-strait relations between China's Communist Party and Taiwan's former ruling Kuomintang (KMT) Party.

There is speculation that China will next target the Pacific where Taipei has formal ties with six countries and China is funding a raft of infrastructure projects. Speculation has also focused on the Vatican – Taipei's only remaining partner in Europe.

In a bid to shore up Taiwan's dwindling international support, this week Ms Tsai hosted Solomon Islands Prime Minister Rick Houenipwela and Nauru President Baron Waqa in Taipei.