WASHINGTON: US Secretary of State Antony Blinken and Defence Secretary Lloyd Austin spoke with NATO Secretary General Jen Stoltenberg and discussed the alliance's coordinated response to Russia's invasion of Ukraine, the State Department said on Thursday.

NATO chief condemns Russia's 'reckless and unprovoked attack' on Ukraine

They also discussed further steps to ensure the security of NATO's Eastern flank, and Blinken stressed that the US commitment to NATO's Article 5 collective defence principle is ironclad, the department said.