President Barack Obama arrived in Poland on Tuesday with a clear mission: reassure eastern European allies of his commitment to the region.<br/> <br />On the first of a four-day European trip, Obama promised continued support in the face of Russia's actions in Ukraine.<br/> <br />(SOUNDBITE) (English) U.S. PRESIDENT, BARACK OBAMA, SAYING:<br/> <br />"Given the situation in Ukraine right now, we've also increased our American presence. We've begun rotating additional ground troops and F-16 aircraft into Poland. And this is going to help our forces train together, it is going to help our forces support NATO air missions."<br/> <br />After visiting with U.S. and Polish air men and women, the president continued his tour with Polish President Bronislaw Komorowski.<br/> <br />Poland and some of its NATO neighbors have been seeking troops on the ground in light of the Ukraine crisis.<br/> <br />However, a big increase in U.S. forces could prompt Moscow to take similar actions.<br/> <br />At a later news conference, Obama anno
