Obama will have meetings with Estonian President Toomas Hendrik Ilves, Prime Minister Taavi Rõivas, and will give a public speech.
Obama will also meet with presidents Andris Berzinš of Latvia and Dalia Grybauskaitė of Lithuania to discuss ongoing cooperation on regional security and policies that support economic growth and to discuss collective defence.
The US President is expected to use the visit on Wednesday to reassure Estonia, Latvia, and Lithuania that the United States and Europe are serious about defending them from a newly aggressive Russia.
Before embarking on a flight to NATO summit in Wales, Obama will also meet Estonian and US soldiers. 150 American soldiers are currently stationed in the country.