Joe Biden pledges air defence systems and insists 'Ukraine can and will stop Putin'

Joe Biden has pledged more support for Ukraine - including air defence systems - as he welcomed NATO member states to a Washington summit marking the organisation's 75th anniversary.

Dogged by rumours over his health, the US president delivered a forceful and determined speech in which he insisted the bloc was "more powerful than ever".

The address came with Russia's invasion of Ukraine intensifying, and Mr Biden's presidential rival Donald Trump continuing to hint the US would leave NATO if he wins November's election.

"Putin wants nothing less, nothing less, than Ukraine's total subjugation... and to wipe Ukraine off the map," Mr Biden said.

"Ukraine can and will stop Putin."