North Korea has fired “several unidentified” projectiles into the sea off its east coast, according to the South Korean military.

The South Korean Office of the Joint Chiefs of Staff said the short range missiles landed to the east of North Korea’s Kangwon province in the Sea of Japan.

South Korea and the US are now the process of analysing what the projectiles were, and officials declined to say whether the launch included ballistic missiles.

“The military is keeping a tight surveillance over the North to cope with further provocations,” South Korean officials said.

South Korea's Yonhap news agency said the launch may have been a ballistic missile, but did not cite a source.

Saturday’s launch comes amid escalating tensions between the two countries and as the US and South Korea begin a large scale military exercise that aims to prepare for the consequences of an attack by the North.

The launch is the first by the North since it test-fired an intercontinental missile on July 28 that is thought could have reached parts of the US mainland.

That missile test prompted Donald Trump to say that if North Korea continued to pose a threat to the US, then the country would be met with “fire and fury the like of which the world has never seen”.

This in turn prompted Pyongyang to warn that it could fire four ballistic missiles at the US island of Guam, surrounding it with a “ring of fire”. The Pacific island is home to US military bases.

The latest missile launches come days after Mr Trump said he thought North Korean leader Kim Jong Un “is beginning to respect us”.

In pictures: North Korea military drill Show all 8 1 /8 In pictures: North Korea military drill In pictures: North Korea military drill North Korea's leader Kim Jong Un watches a military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) KCNA/Handout via REUTERS In pictures: North Korea military drill A military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) is seen in this handout photo by North Korea's Korean Central News Agency (KCNA) KCNA/Handout via REUTERS In pictures: North Korea military drill A military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) is seen in this handout photo by North Korea's Korean Central News Agency (KCNA) KCNA/Handout via REUTERS In pictures: North Korea military drill A military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) KCNA/Handout via REUTERS In pictures: North Korea military drill A military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) KCNA/Handout via REUTERS In pictures: North Korea military drill This image made from video of still images broadcast in a news bulletin by North Korea's KRT, shows what was said to be a 'Combined Fire Demonstration' held to celebrate the 85th anniversary of the North Korean army, in Wonsan, North Korea. KRT via AP Video In pictures: North Korea military drill This image made from video of still images broadcast in a news bulletin by North Korea's KRT, shows what was said to be a 'Combined Fire Demonstration' held to celebrate the 85th anniversary of the North Korean army, in Wonsan, North Korea. KRT via AP Video In pictures: North Korea military drill This image made from video of still images broadcast in a news bulletin by North Korea's KRT, shows what was said to be a 'Combined Fire Demonstration' held to celebrate the 85th anniversary of the North Korean army, in Wonsan, North Korea. KRT via AP Video

“Maybe, probably not, but maybe, something positive can come about,” the US President said.