President Vladimir Putin has updated Russia’s nuclear doctrine, two days after his US counterpart Joe Biden granted Ukraine permission to strike targets deep inside Russia with American-made weapons.

Russian President Vladimir Putin conducts an exercise of Russia's strategic nuclear deterrence forces to train actions of officials on operating nuclear weapons with practical launches of ballistic and cruise missiles,

The US sees no reason to adjust its nuclear posture in response to Russia’s decision to lower the threshold for using atomic weapons, a National Security Council spokesperson said.

Ukraine: The U.S. Embassy in Kyiv received specific information of a potential significant air attack on Nov 20. The Embassy will be closed and recommends U.S. citizens be prepared to immediately shelter in the event an air alert is announced. https://t.co/ah0bpDfULK pic.twitter.com/m8cWXCXT2V

Biden approves provision of antipersonnel landmines for Ukraine; North Korean troops have participated in battle, South Korea says

The U.S. Embassy in Kyiv says it will shut its doors after receiving warning of a potentially significant air attack

The number of North Korean troops stationed inside Russia could grow to 100,000, Ukrainian President Volodymyr Zelenskiy said on Tuesday. Kyiv and its Western allies say North Korea has supplied Russia with weaponry and troops to bolster its full-scale invasion of Ukraine.

North Korean leader Kim Jong Un met with the leader of a Russian delegation in Pyongyang and called for deepening trade, economic and scientific ties between the two countries, state media reported Tuesday.

North Korea ratified a major defence pact with Russia on Tuesday, outlining mutual military aid and requiring both countries to provide each other with immediate military assistance if attacked. Russia had already completed its side of the ratification last week after the pact was signed by Russian President Vladimir Putin and North Korean leader Kim Jong Un.