Vladimir Putin now plans to detonate nuclear bomb in gravest WW3 threat yet

The Russian President announced the tests after he was told by Andrei Belousov, the Russian Defence Minister, that it was "advisable to prepare for full-scale nuclear tests".

It is thought the move is in response to Donald Trump announcing that America would be restarting his own country's nuclear tests.

Mr Putin said: "I am instructing the foreign ministry, the defence ministry, the special services and relevant civilian agencies to do everything possible to collect additional information on the issue, analyse it at the [Russian] security council and make agreed proposals on the possible start of work on the preparation of nuclear weapons tests."

Mr Belousov revealed that nuclear tests could be carried out at short notice at Russia's Novaya Zemlya testing site in the Arctic.

The remote archipelago saw more than 200 nuclear tests under the Soviet Union, including the 1961 test of the most powerful nuclear weapon ever detonated - the 50 megaton Tsar Bomba.

The last explosion carried out by Moscow was in 1990.

Last week, Mr Trump announced the revival of America's nuclear testing for the first time since 1992.

The US President also accused China and Russia of carrying out secret underground nuclear detonations, although both countries, and global experts, have denied this.

North Korea is the only country known to have launched a full-scale nuclear test this country, last detonating an atomic bomb in 2017.

American Energy Secretary Chris Wright said Mr Trump was not referring to full nuclear explosions, however the President is yet to clarify is he ordered test blasts or the testing of delivery systems.

Both Moscow and Washington have already tested nuclear-capable missiles.

In the early hours of Wednesday morning, an unarmed Minuteman III Intercontinental Ballistic Missile was launched by the US from Vandenberg Space Force Base in California.

The missile travelled around 4,200 miles to the Ronald Reagan Ballistic Missile Defence Test Site at Kwajalein Atoll in the Marshall Islands.

Lieutenant Colonel Karrie Wray, Commander of the 576th Flight Test Squadron, called the trial "a comprehensive assessment to verify and validate the ICBM system's ability to perform its critical mission".

And late last month, Russia tested a series of nuclear-capable weapons, including the new Burevestnik nuclear-powered missile.

Russia also launched a nuclear-powered Poseidon "super torpedo", with the country's state media claiming it was capable of engulfing Britain in a radioactive tsunami.

Valery Gerasimov, Russia's Chief of the General Staff, told Mr Putin his country needed to take "appropriate measures" to ensure they are prepared for possible nuclear tests.

He added: "[Otherwise] opportunities for a timely response to the actions of the United States will be lost, since the time required to prepare for nuclear tests, depending on their type, ranges from several months to several years."

The last remaining nuclear arms control treaty between Moscow and Washington is set to expire in February, and no new agreement has been signed - though Mr Putin said in September that Russia would be willing.