The White House has announced that U.S. President Barack Obama is planning a three-day trip to Poland and Spain next month that could be his final trip to Europe while in office.
Obama is traveling to Warsaw on July 7 in order to attend NATO's 2016 Warsaw summit on July 8 and 9 before traveling on to Spain.
The White House said on June 6 it would be Obama's "fifth and final summit with NATO leaders."
Russia's continued testing of NATO resolve in Eastern and Central Europe is expected to be on the agenda of the talks.
Poland's President Andrzej Duda has said NATO bases in Central Europe are a priority for the Warsaw Summit.
Duda has said there needs to be "a greater presence of NATO" across "the whole of Central and Eastern Europe" to ensure security against a resurgent Russia.