For anyone wondering why Biden would need to approve this, here’s an excerpt from the article:
While Polish Foreign Minister Radoslaw Sikorski said at the time that the matter was still under discussion, Defense Minister Wladyslaw Kosiniak-Kamysz explained that a decision by all of NATO’s member states would be necessary to take this step.
It’s interesting that it specifically mentions the Series X. My understanding is that anything released on Series X must also run on the Series S.