TALLINN, Estonia (AP) — U.S. Vice President Mike Pence has arrived in Estonia for meetings with the presidents of northern Europe's three Baltic nations.

The vice president and his wife, Karen Pence, arrived in the Estonian capital, Tallinn, on Sunday to kick off a four-day European tour that also includes stops in Georgia and Montenegro.

Pence is scheduled to meet with the leaders of the Baltics — Estonia, Latvia and Lithuania — on Monday. He is expected to pledge Washington's commitment to NATO's mutual defense, an important issue for the former Soviet republics that border Russia.

On Sunday, he plans to hold talks with Estonian Prime Minister Juri Ratas.

Issues include Estonia's current holding of the European Union presidency, trade, cybersecurity and the continuing tensions in the Baltic Sea region, where Russia and NATO have increased their military presence in recent years.