Tech billionaire says Kyiv meant to sink fleet; biographer says SpaceX owner was warned by Russian ambassador that Crimea attack would lead to nuclear retaliation

In new public testimony, former president spars with New York AG suing him for fraud, says he never expected his inflated financial statements would be taken seriously

Past year has prompted warnings of armageddon amid war in Ukraine and concerns over higher rate of warming, but has also seen COVID pandemic recede and other positive signs

President says he knows Putin and Russian president not messing around when he talks about using weapons of mass destruction, but White House maintains nuclear posture unchanged

Warning comes as US steps up aid to Ukraine and declares it wants to weaken Russia, with Foreign Minister Lavrov saying there is a 'real' danger of World War III breaking out

Foreign minister's comments come days after Putin ordered his nuclear forces on high alert

Russian leader says move a response to 'aggressive statements' by NATO member countries; UK foreign secretary says world must prepare 'for Russia to seek to use even worse weapons'

US, UK, France, Russia and China set aside tensions to say nuclear war 'must never be fought'

The president has the sole authority to order a US nuclear attack, but some safeguards do exist