Japan’s defence minister took a veiled swipe at China on Sunday, pledging to keep strengthening the military despite Beijing’s criticism of Tokyo’s increasingly muscular security stance.

Under the prime minister, Sanae Takaichi, Japan has quickened its pivot to a more proactive defence policy, further shaking off – with US encouragement – its pacifist outlook in place since the end of the second world war.

The change has drawn frequent rebukes from Beijing, which has accused Tokyo of following a reckless policy of “new militarism” that could destabilise the region.

The Japanese defence minister, Shinjiro Koizumi, hit back on Sunday, saying “nothing could be further from the truth”.

“Think about it. There is a country that has a huge arsenal of nuclear weapons and strategic bombers,” Koizumi said at the annual Shangri-La Dialogue in Singapore.

“Japan has neither of such weapons. And yet, Japan is labelled (as) ‘new militarism’. Isn’t it strange?” he said, without mentioning China by name.

China is thought to possess hundreds of nuclear warheads and has been rapidly developing its military in recent years.

A diplomatic spat between the Asian rivals has been rumbling since Takaichi suggested in November that Japan might intervene militarily if China were to attempt to seize Taiwan, the self-ruled island that Beijing claims is part of its territory.

Koizumi said that China was expanding its military capabilities “without sufficient transparency” and that its military activities were “a matter of serious concern for Japan”.

Tokyo would “steadily build up its defence capabilities and make continuous updates with a high degree of transparency”, including in the fields of artificial intelligence, uncrewed systems and cyber and space defence, he said.

“Japan’s past as a peace-loving nation has been valued by the region and by [the] international community. This fact will not be shaken by false claims, because it is a fact,” he said.

The Shangri-La Dialogue is Asia’s top defence forum, bringing together security officials and experts from about 45 countries.

In contrast to Japan – and its ally the US – China has sent a watered-down delegation that does not include its defence minister, Dong Jun, for the second year running.

Koizumi said he was “feeling sad that we were unable to have the opportunity to have a meeting this time”.