Former US deputy national security adviser Matt Pottinger has said that Japan would step up militarily to defend Taiwan if China moved to reunify the island with its mainland by force.
In a panel discussion on Tuesday with other top Trump administration officials, Pottinger said Japan first suggested a quadrilateral alliance with the US, India and Australia - now known as the "Quad" - as a defence strategy against China, according to South China Morning Post (SCMP).
"Some of the key pillars of our strategy in the Indo-Pacific region were ideas that we borrowed and adapted and shared and collaborated on with Japan," he said.
The ex-deputy NSA said that former Japanese Prime Minister Shinzo Abe had come up with the whole idea of a quadrilateral format in 2006 and 2007. "There's a saying in the Japanese military: 'Taiwan's defence is Japan's defence.' And, and I think that Japan will act accordingly," he said.
Pottinger, who is considered one of the key architects of the Trump administration's hardline China policies, made these remarks amid a series of incursions by Chinese warplanes into Taiwan's southwest air defence identification zone.
Meanwhile, former US Secretary of State Mike Pompeo and former national security adviser Robert O'Brien offered somewhat supportive comments about the way Biden has taken negotiations with the Quad forward, SCMP reported.
Pompeo said that the leaders of the Quad countries were looking at the United States very clearly and could see that there was a time limit to an administration.
"I hope the next administration - they've said good things about this, they've applauded regularly, one of the few things they've given the Trump administration some credit for - I hope they'll seriously work to go build this out," he added.
On the other hand, O'Brien called Biden's approach to the alliance "positive". "The initial soundings from ... the Biden administration are very positive when it comes to the Quad and strengthening those relationships," O'Brien said. "I hope they follow through, and I wish them luck on that front and Godspeed in that endeavour because it's a very powerful group," he said.
Meanwhile, Pottinger denied that the Trump administration had badly strained US alliances in the Indo-Pacific region. "I've never seen an empirical fact produced to suggest that our alliances did anything other than strengthen over the course of the Trump administration," he said.
Beijing claims full sovereignty over Taiwan, a democracy of almost 24 million people located off the southeastern coast of mainland China, despite the fact that the two sides have been governed separately for more than seven decades.