US President Joe Biden completes his long trip abroad to Poland, where he met with Ukrainian officials and the Polish president. Biden meets with Ukrainian refugees before delivering what the White House described as a “keynote address” this afternoon. Speaking to Polish President Andrzej Duda, the US president said that peace in Europe was directly linked to stability in the United States, adding that the lack of action in two world wars was “haunting us again”. Biden also called NATO Article 5 a “sacred commitment.” Earlier, Biden interrupted a meeting between Ukrainian Foreign Minister Dmytro Kuleba and Defense Minister Oleksii Reznikov and their US counterparts, Foreign Minister Antony Blinken and Defense Minister Lloyd Austin. Reznikov said he was cautiously optimistic after the meeting. The United States has received assurances that there will be additional defense assistance to Ukraine, said Ukrainian Foreign Minister Dmitry Kuleba. Biden’s trip comes after a series of special summits this week in Brussels. Following the summit, Biden said he supported Russia’s withdrawal from another summit, the G20, scheduled for November, although other members of the group would have to sign. And it issued a vague warning that the United States would respond to possible use of chemical weapons on the battlefield. However, he maintained that immediate US military intervention in Ukraine would lead to disaster, and defended a sanctions regime that has so far prevented Russian President Vladimir Putin from stepping up his attack. CNN’s Kevin Liptak contributed to the report in this post.