Japan is reportedly mulling acquisition of Tomahawk cruise missiles to counter the increasing threats from North Korea. Authorities are said to be working on plans to acquire and deploy the advanced weapons without violating the country's pacifist constitution.

Tensions on the Korean peninsula have escalated in recent months with Pyongyang's repeated threats against the US, South Korea and Japan. The US has said that both its close allies in the region face a serious threat from North Korea.

According to a source cited by Japan's Kyodo news agency, the government is keen on boosting its defence capabilities. The unnamed source added that funds for the purpose will be allocated in the 2018 budget.

But there are fears that deploying such weapons could prompt a strong backlash from domestic opposition parties against the ruling establishment.

According to reports, in addition to Tomahawk cruise missiles, the government prefers subsonic all-weather long-range projectiles. The weapons will have to be fitted on Japan's Aegis class vessels, which need modifications.

One of the key clauses of the Japanese constitution states "land, sea, and air forces, as well as other war potential, will never be maintained".

However, in recent months, the ruling party, Liberal Democratic Party (LDP), has been calling for significant measures to boost Japan's defence capabilities.

In March, the LDP's key policy panel, headed by former defence minister Itsunori Onodera, made several recommendations including deployment of Terminal High Altitude Area Defence (Thaad).