NATO leaders will approve the deployment of four additional battlegroups to Hungary, Romania, Bulgaria and Slovakia at the March 24 summit, US Ambassador to NATO Julianne Smith said on CNN.

It is not just a national force, she said, and more details will be made public on Thursday. She stated that NATO was in talks about a medium- and long-term presence of forces on its eastern flank.

Commenting on Poland's proposal for a NATO peacekeeping mission in Ukraine, she said it was not a dead question but there were a lot of open questions and the allies want to know more about the Polish proposal.