President Joe Biden is set to embark on a five-day trip to Europe, during which he will attend the NATO summit in Lithuania. The summit comes at a crucial time as NATO faces thorny divisions over whether to expand the alliance further. Ukraine's desire to join NATO and Sweden's stalled bid to do the same are expected to dominate the discussions.

Ukraine's push to join NATO has garnered mixed reactions from members. Some, like Lithuania, welcome the idea, while others, like the United States and Germany, warn that it could escalate tensions with Russia. Biden's meetings in Europe could become contentious as he navigates these divisions.

Biden has been clear that the United States supports Ukraine and will provide them with arms and capabilities. However, he has been noncommittal about Ukraine's immediate NATO membership. NATO has historically rejected countries in the midst of an active invasion or occupation.

The trip will also be an opportunity for Biden to rally Western support for Ukraine and emphasize the importance of redoubling efforts to support the country. He will argue that his administration has delivered on its promise to repair America's alliances and highlight NATO's response to Russia's aggression.

Overall, Biden's ability to keep NATO unified in responding to Russia's aggression will be closely watched during his trip.--------------