By Luiza Ilie, Libby George and Gergely Szakacs BUCHAREST/LONDON (Reuters) -Romanian centrist Nicusor Dan may have defied the odds to win the presidency, but now he faces an even more daunting task: forming a government that can implement years of painful austerity - and revenue-raising measures - to tame Europe's widest fiscal deficit.

As a member of the EU and one of the easternmost members of the NATO military alliance, Romania plays a pivotal role in Western security infrastructure.

Romania’s pro-European Union, centrist presidential candidate Nicușor Dan won the country’s election Sunday, defeating his ultranationalist rival in a shocking upset.