North Korea appears to be developing sophisticated new warheads designed to penetrate Japan’s ballistic missile shield, Tokyo has said.

The warning came as the UK, France and Germany issued a joint statement warning Kim Jong-un’s regime over recent “repeated provocative launches”, which the three said were in violation of UN Security Council resolutions.

North Korea fired two more short-range ballistic missiles into the Sea of Japan on Saturday, the seventh such test in a month.

And Japan’s defence minister, Takeshi Iwaya, said analysis showed the rockets were a new type of missile which followed irregular trajectories.

Japan and the US have Aegis destroyers deployed in the Sea of Japan, armed with interceptor missiles designed to destroy warheads in the air. Japan also plans to build two land-based Aegis batteries to bolster its ballistic missile shield.

North Korea military parade celebrating nation's 70th anniversary Show all 18 1 /18 North Korea military parade celebrating nation's 70th anniversary North Korea military parade celebrating nation's 70th anniversary Participants wave flowers AFP/Getty North Korea military parade celebrating nation's 70th anniversary North Korea's leader Kim Jong Un (R) waves with China's Chairman of the Standing Committee of the National People's Congress Li Zhanshu (L) from a balcony AFP/Getty North Korea military parade celebrating nation's 70th anniversary Airplanes forming the number 70 fly in formation and fire flares AP North Korea military parade celebrating nation's 70th anniversary North Korean performers dance EPA North Korea military parade celebrating nation's 70th anniversary North Korean military officers applaud near portraits of late North Korean leaders Kim Il Sung and Kim Jong Il AP North Korea military parade celebrating nation's 70th anniversary North Korean tanks roll past AP North Korea military parade celebrating nation's 70th anniversary Participants cheer as they take part in a parade for the 70th anniversary of North Korea's founding day in Pyongyang, North Korea, Sunday, Sept. 9, 2018. North Korea staged a major military parade, huge rallies and will revive its iconic mass games on Sunday to mark its 70th anniversary as a nation. (AP Photo/Ng Han Guan) Ng Han Guan AP North Korea military parade celebrating nation's 70th anniversary Korean People's Army (KPA) soldiers take part AFP/Getty North Korea military parade celebrating nation's 70th anniversary Korean People's Army (KPA) soldiers march AFP/Getty North Korea military parade celebrating nation's 70th anniversary Participants march during a mass rally on Kim Il Sung square in Pyongyang AFP/Getty North Korea military parade celebrating nation's 70th anniversary A girl reacts during a parade AP North Korea military parade celebrating nation's 70th anniversary North Korean leader Kim Jong Un, right, reacts as he chats with China's third highest ranking official, Li Zhanshu AP North Korea military parade celebrating nation's 70th anniversary People carry flags in front of statues of North Korea founder Kim Il Sung (L) and late leader Kim Jong Il Reuters North Korea military parade celebrating nation's 70th anniversary Performers take part in a concert at the Pyongyang Indoor Stadium AFP/Getty North Korea military parade celebrating nation's 70th anniversary North Korean artillery roll past AP North Korea military parade celebrating nation's 70th anniversary Students perform Reuters North Korea military parade celebrating nation's 70th anniversary Soldiers march during a military parade Reuters North Korea military parade celebrating nation's 70th anniversary Participants wave flowers AFP/Getty

Those defence systems, however, are designed to counter projectiles on regular – and therefore predictable – trajectories, and any variation in flight path would make interception trickier.

South Korea’s defence ministry said it was working with the US to conduct a detailed analysis of the latest North Korean launches.

Yet despite the tests stoking growing alarm among American allies in the region, Donald Trump appeared to dismiss them as unimportant in comments made on Sunday – even as he met Shinzo ​Abe, the Japanese prime minister.

“I’m not happy about it, but then again he’s not in violation of an agreement,” Mr Trump said, apparently referring to commitments – made by Mr Kim during their leaders’ summits – not to conduct any more nuclear or long-range missile tests.

Without naming Mr Trump, the statement late on Tuesday from America’s key European allies showed that they do not agree.

After the UN Security Council discussed the launches behind closed doors, the UK, France and Germany said that it was “vital that the Security Council shows unity in upholding its resolutions”.

“International sanctions must remain in place and be fully and strictly enforced until North Korea’s nuclear and ballistic missile programmes are dismantled,” the statement read.

The European countries blamed Mr Kim’s regime for the “current dire situation of its people” and stressed that making progress on denuclearisation was the only way to guarantee “a brighter future for the people of North Korea”.

North Korean state media said the country’s leader oversaw Saturday’s test personally, and that it involved a “newly developed super-large multiple rocket launcher”.

The apparent boast of Pyongyang’s growing arsenal came at a time of strained relations between Japan and South Korea, at odds over historical abuse claims and a modern-day trade dispute.