Live updates | NATO chief: alliance in 'biggest challenge'

NATO Secretary-General Jens Stoltenberg says the military alliance faces its “biggest challenge” since World War II amid the war in Ukraine.

Stoltenberg said at the start of the NATO summit in Madrid on Wednesday that the allies are meeting “in the midst of the most serious security crisis we have faced.”

“This will be a historic and transformative summit,” he told reporters.

Stoltenberg said the alliance is going to agree on deterrence to be able to deploy more combat formations and get more pre-positioned equipment in Eastern Europe by next year.

Ukrainian President Volodymir Zelenskyy is expected to address the 30 leaders via video link Wednesday, as Russia’s invasion stretches into its fifth month.

The gathering has already seen a breakthrough agreement between Turkey and Finland and Sweden for the Nordic countries to begin their accession process.

The asked to join the alliance after witnessing Russia’s brutal attack on its neighbor Ukraine, but Turkey had some misgivings that were overcome Tuesday.