He says Russia’s invasion of Ukraine is the "biggest security crisis in a generation" and "we stand united to keep our alliance strong and our people safe"
Stoltenberg says Nato has agreed to strengthen their defences by moving 40,000 troops to its eastern flank in response to Russia's invasion
He confirmed four new battlegroups will be sent to Slovakia, Hungary, Bulgaria and Romania
Stoltenberg also said cyber defences are being strengthened and Nato will also help Ukraine defend itself against "biological, chemical, radiological and nuclear threats"
He says the use of chemical weapons "will totally change the nature of the conflict, it will be a blatant violation of international law and it will have widespread consequences"
Putin’s invasion of Ukraine has changed our security environment for the long term and Nato is prepared for the “long haul”, he says