Following a historic thaw in relations that has led to a deepening of military ties between South Korea and Japan, the two countries are targeting a new area of collaboration: climate and energy security.

Their governments are stepping up efforts to promote the use of hydrogen and ammonia as emission reduction tools for their industrial and power generation sectors. But the bilateral effort has been heavily criticised by environmental campaigners, who argue it could slow the global transition to renewable energy.

In a meeting in Seoul last month, Japanese prime minister Fumio Kishida and South Korean president Yoon Suk Yeol agreed to accelerate efforts to create a global supply chain for hydrogen and ammonia after unveiling the joint initiative last November.