Leaders of the world’s largest defense alliance will convene in Madrid this week for the NATO 2022 summit.

The high-stakes meeting from June 28 to 30 comes at a time of heightened global tension amid Russia’s war in Ukraine.

NATO Secretary-General Jens Stoltenberg says the western military alliance will boost its high readiness forces to "well over 300,000" in response to Russia's unprovoked invasion of Ukraine.

Speaking ahead of a NATO summit in Madrid, Stoltenberg said on June 27 that the alliance will enhance its battle groups on its eastern flank up to brigade levels.

"We will strengthen our forward defenses...We will transform the NATO Response Force and increase the number of our high readiness forces to well over 300,000," Stoltenberg told reporters.

The NATO Response Force, currently has about 40,000 troops.

"I expect that allies will state clearly that Russia poses a direct threat to our security, to our values, to the rules-based international order," Stoltenberg added.