Biden tells NATO in forceful speech: Ukraine will stop Putin

US President Joe Biden pledged to forcefully defend Ukraine against Russia's invasion at the NATO summit in Washington on Tuesday, using the global stage to try to show allies at home and abroad that he can still lead.

Biden, 81, has endured 12 days of withering questions about his fitness for office as some of his fellow Democrats on Capitol Hill and campaign donors fear that he will lose the Nov. 5 election after a halting debate performance on June 27.

"(Vladimir) Putin wants nothing less, nothing less, than Ukraine's total subjugation ... and to wipe Ukraine off the map," Biden said in his welcome to NATO member states to the summit, referring to the Russian president. "Ukraine can and will stop Putin."

The White House is hoping he can turn the page on a difficult period in his presidency with his highest profile policy speech since the debate, although some diplomats at the summit said the damage was hard to erase.

On Tuesday, Biden spoke off of a teleprompter with a strong and confident voice and largely avoided the verbal flubs and signs of confusion that marked his debate performance.

Biden was framed by the gilded walls of the federal hall where the treaty creating NATO was signed, his speech bookended by stirring musical performances by the US Marine Corp band.

"Today NATO is stronger than it's ever been in its history," he said.

The centerpiece of the NATO summit is set to be new commitments of military and humanitarian aid to Ukraine. 

US Secretary of State Antony Blinken said the summit would "further strengthen" the war-torn country's path to NATO membership.

Reuters