Strict water restrictions come into force for millions of people in California as the US west coast continues to experience a crippling drought.

President Vladimir Putin has put Russia's nuclear forces on high alert. The theory is that the possibility of mutually assured destruction is the strongest of reasons not to press the button. But the pressure is mounting.

The European Union says it will begin shipping arms to Ukraine. This is the first time in its history that it has supplied arms in a conflict.

More than 800 million people around the world use the social media video platform TikTok. However, some governments around the world are concerned that the Chinese-owned app allows the Chinese government to access people's data.

Theresa May gives her first speech as Britain's new prime minister, outlining her priorities for the UK with a focus on domestic issues.