ROUGH CUT (NO REPORTER NARRATION).<br/> <br />STORY: U.S. President Barack Obama landed in Poland on Tuesday (June 3) at the start of a four-day trip to Europe meant to reassure allies there that the United States has their backs in the wake of the Russian intervention in Ukraine.<br/> <br />In Poland, Ukraine's western neighbour and a U.S. NATO ally, Obama meets with leaders including Ukraine's president-elect, Petro Poroshenko, and is expected to address criticism he has not done enough to push back against Moscow after it annexed Crimea in March.<br/> <br />Obama began his day by meeting Polish President Bronislaw Komorowski at Warsaw airport. The two leaders visited U.S. and Polish airmen where Obama restated U.S. commitment to Poland's security.<br/> <br />Obama said the U.S. had stepped up its military presence in Poland.<br/> <br />Later Obama will meet Prime Minister Donald Tusk, followed by a session with other central and eastern European leaders who are gathered in Warsaw.<br/> <br />His visit coincides
