U.S. President Barack Obama has left Washington on a four-day European trip aimed at reassuring NATO allies of active U.S. support, as regional tensions over Russia's role in Ukraine continue to rise.
Obama will hold a full day of talks Wednesday in the Estonian capital with the presidents of Estonia, Latvia and Lithuania. The meetings in Tallinn, 200 kilometers from the Russian border, come in response to mounting concerns about Russian military involvement in Ukraine and possible Russian threats to the Baltic states.
The president has described the Baltic talks as a means of showing the three former Soviet republics "that we mean what we say with respect to our treaty obligations."
Obama on Thursday joins the leaders of 27 other NATO nations for a key summit aimed at sharpening Western support for Ukraine, as Kyiv battles a months-long rebellion by pro-Russian separatists near the Russian border.
The summit in Wales is set to focus on proposals to establish a rapid-reaction NATO force capable of deploying quickly to eastern Europe. Ukraine President Petro Poroshenko is due to attend.
Russia has voiced strenuous opposition to any such NATO presence near its borders, and Tuesday said it would review its own military strategies if - as expected - NATO members endorse the creation of the force.
NATO Secretary General Anders Fogh Rasmussen unveiled the new "very high readiness force" on Monday. He said several thousand troops could be deployed on very short notice, to give the alliance a more visible presence in eastern Europe.
Russian Foreign Minister Sergei Lavrov - speaking Tuesday in Moscow - told reporters that Ukraine's push to join the NATO alliance is undermining efforts to end the four-month rebellion in eastern Ukraine.
Lavrov spoke a day after envoys from Ukraine, Russia, the separatist movement and the Organization for Security and Cooperation in Europe met in Belarus, seeking to find agreement on a truce.
Separatists dropped their earlier demand for full independence in the Russian-speaking east. Representatives said they were ready to negotiate a settlement respecting Ukraine's territorial integrity in exchange for broad autonomy in Russian-speaking eastern regions.
There has been no formal response from Kyiv.