Japan is considering exporting lethal weapons by revising its strict guidelines on the transfer of defense equipment under its postwar pacifist Constitution, a government source said Thursday.

One of the ideas under discussion is that the government will realize such exports on condition that they would help boost the deterrence of the importing nation and contribute to Japan's security environment, according to the source.

Ground Self-Defense Force members listen to a speech by Japanese Prime Minister Fumio Kishida during his visit to the GSDF's Asaka base straddling Tokyo and Saitama Prefecture on Nov. 27, 2021. (Pool photo) (Kyodo) ==Kyodo

The plan comes as the government has been unable to ship lethal weapons to Ukraine, although it called for anti-tank missiles from Tokyo after Russia's invasion started in late February.

Japan declined the request because of its "three principles" on the transfer of defense equipment, which effectively ban weapons exports except for the purpose of jointly developing or producing them with a foreign country.

For Ukraine, Japan instead started sending protective gear such as bulletproof vests and helmets in March.

The government is planning to revise the preamble of the principles by stating that exporting weapons is an "important diplomatic and defense policy tool," according to the source.

To enable the Self-Defense Forces to provide other countries with their arms and ammunition, the government is also hoping to amend the SDF Law, the source added.

It believes promoting weapon exports will help support Japan's defense-related industry, and the new direction is expected to be stipulated in the National Security Strategy, the nation's long-term security and diplomacy policy guideline, which will be updated by the end of this year.

However, opposition to relaxing the principles remains strong within Komeito, the Liberal Democratic Party's junior coalition partner.

Depending on discussions with Komeito, the LDP and the Defense Ministry may not be able to achieve their goal.

The three principles specify under what condition the overseas transfer of Japan's defense equipment should be banned and allowed. For example, recipient countries are obliged to ensure proper control over equipment delivered by Japan.

Japan had long maintained a more stringent ban on arms exports, but then Prime Minister Shinzo Abe eased it in 2014 and adopted the current principles.