Sofia (AFP) - EU member Bulgaria headed into fresh political turbulence Monday after a former air force commander seen as sympathetic to Russia triumphed in presidential elections, prompting Prime Minister Boyko Borisov to quit.
In his victory speech, Rumen Radev reiterated his opposition to EU sanctions on Russia and praised new US President-elect Donald Trump for "seeking more dialogue" with President Vladimir Putin.
"This gives a lot of hope for reducing (the risk) of confrontation, particularly in Syria" where Russia and the US are backing opposite sides in a bloody civil war, the fighter pilot said.
He won 59.4 percent of the vote, well ahead of the more Western-leaning Tsetska Tsacheva, Borisov's uninspiring hand-picked candidate, who garnered just 36.2 percent, near-complete official results showed Monday.
The outcome was mirrored in Moldova, a small ex-communist nation wedged between Ukraine and Romania, where the pro-Russian Igor Dodon beat his pro-European rival Maia Sandu to the presidency.
"If Bulgarians want a political crisis then they shall have one," Borisov said on Sunday evening as he threw in the towel.
Bulgaria is now set for months of political inertia. Borisov on Monday formally handed his resignation to parliament.
An interim government will govern until fresh elections, which are not expected until March at the earliest and could well be inconclusive.
- Anti-establishment -
Moscow on Monday welcomed Radev's victory and called for "the expansion of cooperation" with Bulgaria.
Radev, 53, due to take office on January 22, has no political experience and was little known before being backed by the opposition Socialists to run for president.
Like other anti-establishment politicians -- not least Trump but also populists around Europe -- he struck a chord with voters by attacking the status quo and stressing issues like national security and immigration.
Experts also saw his victory as a protest vote at Borisov's failure to improve the lot of ordinary Bulgarians -- the average monthly salary is just 480 euros ($535) -- and to tackle rampant corruption.
Radev's clear support for the lifting of sanctions on Russia and ambivalent statements about the EU, NATO and Crimea have prompted speculation that Bulgaria could lean more towards Moscow.
This could further undermine unity within the EU, already reeling from June's Brexit vote, in its stance towards Russia just as Trump's surprise election victory raises worries about the future of NATO.
"General Radev's victory represents the unfolding of a pro-Russian scenario in Bulgaria so that the country supports Russian interests in the EU and NATO," political expert Antoniy Galabov told AFP.
But at the same time Radev, stressing that he is a "NATO general trained in the US", has said there is "no alternative" to Bulgaria's membership of the European Union and the NATO military alliance.
Bulgaria and Russia have deep historical, cultural and commercial ties and the country has long walked a tightrope in its relations with Moscow and the West.
Bulgaria's outgoing president has been sharply critical of Moscow and Borisov's government angered Moscow by banning Russian supply flights to Syria from using its airspace last September.
Antoniy Todorov at New Bulgarian University pointed out that as president -- a largely ceremonial but highly respected position -- Radev on his own can do little.
"The president only has influence if the government is on the same wavelength... Radev is not going to pull Bulgaria out of NATO," Todorov said.
In a tongue-in-cheek cyber attack, hackers on Monday diverted users trying to access Radev's website to the Kremlin's official page.