China and Russia have dispatched spy vessels to shadow a fleet including a US aircraft carrier heading to North Korean waters.

Beijing has sought Moscow’s help in averting the mounting crisis over Pyongyang’s repeated nuclear tests.

US President Donald Trump has sent a navy group led by the aircraft carrier Carl Vinson into the region as a signal to the secretive dictatorship about its nuclear programme.

North Korea has defied repeated economic sanctions and international pressure over its nuclear regime, which saw it carry out two tests in 2016 and one so far this year, and has vowed a “merciless response” to any US provocation.

Mr Trump described the force as an “armada” and said the submarines being sent were “far more powerful than the aircraft carrier”.

Japanese newspaper Yomiuri Shimbun cited “multiple sources” within their country’s government which said China and Russia had dispatched vessels to chase the USS Carl Vinson.

China is widely seen as the only country that can rein in Pyongyang but has traditionally refused to do so in order to prevent the regime collapsing and a subsequent refugee crisis on its border.

In recent months it has demonstrated signs that it wants to help the international community force North Korea to back down – in February it banned all coal imports from the country and last week deployed 150,000 troops to the border.

In pictures: North Korea marks the Day of the Sun Show all 16 1 /16 In pictures: North Korea marks the Day of the Sun In pictures: North Korea marks the Day of the Sun North Korean women soldiers take part in a military parade in Pyongyang on 15 April AFP/Getty Images In pictures: North Korea marks the Day of the Sun A huge military parade in Pyongyang marks the 105th birth anniversary of Kim Il Sung, the country's late founder and grandfather of current ruler Kim Jong Un AP In pictures: North Korea marks the Day of the Sun North Korean leader Kim Jong-un waves during a military parade on 15 April 2017 AP In pictures: North Korea marks the Day of the Sun North Korean soldiers carry flags and a photo of Kim Il-sung during a military parade in Pyongyang on 15 April AP In pictures: North Korea marks the Day of the Sun Soldiers march across Kim Il Sung Square during a military parade on 15 April AP In pictures: North Korea marks the Day of the Sun What military experts say appears to be a North Korean KN-08 inter-continental ballistic missile is paraded across Kim Il Sung Square during a military parade on 15 April AP In pictures: North Korea marks the Day of the Sun Women wearing traditional Korean dress wave flowers and shout slogans as they pass Kim Jong-Un during a parade in Pyongyang on 15 April AFP/Getty Images In pictures: North Korea marks the Day of the Sun North Korean female soldiers march during a parade for the 'Day of the Sun' festival on Kim Il Sung Square in Pyongyang on 15 April EPA In pictures: North Korea marks the Day of the Sun Military vehicles carry missiles with characters reading 'Pukkuksong' during a military parade marking the 105th birth anniversary of Kim Il-sung in Pyongyang on 15 April 2017 EPA In pictures: North Korea marks the Day of the Sun Attendees carry sheets in the colours of North Korea's national flag during a military parade in Pyongyang on 15 April Reuters In pictures: North Korea marks the Day of the Sun A soldier salutes from atop an armoured vehicle during a military parade in Pyongyang on 15 April Reuters In pictures: North Korea marks the Day of the Sun A North Korean woman cries as she looks towards Kim Jong-un during a parade on 15 April AP In pictures: North Korea marks the Day of the Sun University students carry the national flag and two bronze statues of the late leaders Kim Il-sung and Kim Jong-il during a military parade on 15 April AP In pictures: North Korea marks the Day of the Sun Missiles are driven past Kim Jong-un and other high ranking officials during a military parade marking the Day of the Sun in Pyongyang on 15 April Reuters In pictures: North Korea marks the Day of the Sun North Korean leader Kim Jong-un waves from a balcony during a parade for the 'Day of the Sun' festival in Pyongyang on 15 April 2017 EPA In pictures: North Korea marks the Day of the Sun Missiles are driven past Kim Jong-un and other high ranking officials during a military parade marking the Day of the Sun in Pyongyang on 15 April Reuters

Mr Trump’s National Security Advisor Lieutenant General HR McMaster said “all options are on the table” including military intervention when it comes to North Korea.

Beijing has urged both countries to avoid an “irreversible route” to war and warned that conflict could break out “at any moment”.

Chinese Foreign Minister Wang Yi said: “If a war occurs, the result is a situation in which everybody loses and there can be no winner. It is not the one who espouses harsher rhetoric or raises a bigger fist that will win.”

The Korean peninsula has been divided since the end of the Second World War when the USSR and US jointly administered the north and south respectively after taking over following the end of the Japanese occupation.

When forces under North Korean leader Kim il-Sung invaded the south in 1950, the newly formed UN, led by the US, intervened to stop the south falling to Kim’s version of nationalistic communism.

After three years of fighting, the two sides agreed an armistice along the 38th parallel which divided the country in two.