WASHINGTON, May 25  -- The United States looks forward to working with the next president and the new parliament of Ukraine to support the country's efforts to enact important reforms, U.S. President Barack Obama said on Sunday.

Ukrainian voters went to the polls Sunday to elect a new president for the next five years in an early election called three months after the ouster of former president Viktor Yanukovych.

"This election is another important step forward in the efforts of the Ukrainian government to unify the country and reach out to all of its citizens to ensure their concerns are addressed and aspirations met," Obama said in a statement released by the White House.

The United States remains committed to working with Ukraine and other partners to find a peaceful resolution to the conflict, said Obama, who arrived at the Bagram air base in north of Kabul, the main U.S. base in Afghanistan, for an unannounced visit to U.S. troops on Sunday.

The president also congratulated the people of Ukraine on making their voices heard by voting in the election and praised " courageous" Ukrainians who were able to cast their ballots in parts of eastern Ukraine "where Russian-backed separatist groups sought to disenfranchise entire regions."

"We commend the resolve of all those who participated, as well as the efforts of the Ukrainian government to conduct these elections in the face of those threats," Obama said.

Exit polls showed that Petro Poroshenko, a wealthy businessman and independent politician, has won Ukraine's presidential election with an absolute majority.