U.S. President Barack Obama and Italian Prime Minister Matteo Renzi met in Rome Thursday, discussing a wide range of topics ranging from the crisis in Ukraine, Italy's nascent economic turnaround, to the nature of leadership. Obama expressed admiration for what he called Renzi's "energy, vision, and ambition of ideas" and said he was confident in the leadership skills of the 39-year-old, who became Italy's prime minister only five weeks ago. Obama also praised Europe's improving economic health: "It was just a year and a half ago or two years that we were very worried about the euro zone spiraling out of control," he said. Regarding Ukraine, Renzi said "We have to do everything we can do for the Ukrainian people, but at the same time it is important not to promise and then fail to deliver," he said. Obama seemed to take a small jab at the Europen Union for spending less than the U.S. on defense in per capita terms. Speaking in a context of peacekeeping and acting as a deterrent, Obama noted that the U.S. spends 3 percent of GDP on defense ("Perhaps more if problems in the word continue," he said), while Europe spends just 1 percent. "Everyone must do their fair share," Obama said.