The policy chief of Japan’s ruling Liberal Democratic Party has urged US President Donald Trump to reconsider plans for reciprocal tariffs, warning they could undermine security across the Indo-Pacific region Reuters reports.

Former defence minister Itsunori Onodera, speaking in Washington at the Center for Strategic and International Studies, expressed particular concern about the potential impact on Southeast Asia. His remarks also coincided with the current visit to the region by Japanese Prime Minister Shigeru Ishiba.

Onodera said that the countries of the 10-member Association of Southeast Asian Nations (ASEAN) could become more distant from the United States as a result of the tariff measures. He called for a reconsideration of the policy, highlighting the importance of maintaining close ties.

Onodera made no direct reference, however, to recent efforts by China to create an anti-US alliance of sorts to help counter the US tariffs – something Japan is wary of as potentially running counter to China containment efforts by Tokyo, but also something the US is already hitting back against in the form of increased tariffs on solar exports from nations recently visited by Chinese President Xi Jinping.

Japan is already facing 24% tariffs on its exports to the United States. ASEAN nations have also been targeted, although the bulk of these threatened tariffs have at present been suspended as negotiations with the US continue. A universal 10% tariff does remain in place though, in addition to a 25% duty on cars, a critical sector for Japan’s export-driven economy.

Onodera conveyed deep concerns from Prime Minister Ishiba regarding ASEAN, noting that the tariffs could have significant consequences not only economically but also in terms of security the Reuters report continued. He emphasised that the stability of East Asia depended on strong deterrence measures jointly maintained by the United States and Japan, and cautioned against actions that could weaken these efforts.

In addition he pointed to Japan’s role in maintaining US naval vessels and the broader security collaboration between the two countries, which he said was particularly vital amid rising threats from China, Russia and North Korea.

Onodera also stressed Japan’s position as the largest foreign investor in the United States, contributing significantly to job creation and boosting US exports. He warned that the tariffs could weaken Japanese companies, potentially diminishing their ability to invest in the US economy.