Russia's President Vladimir Putin speaks at a news conference at the end of the G-20 summit in Brisbane, Australia, Nov. 16, 2014. Putin said on Sunday that there's a "good chance of resolution" in the Ukraine conflict, contradicting Western concerns over an escalation in fighting in the southeast of the country. Reuters

Russia's ties to the Ukraine separatist movement poses the biggest security risk to world markets because of ongoing sanctions and falling oil prices that threaten the Russian economy, according to a Bloomberg Global Poll of international investors. Poll participants said Russia posed a greater security risk than Islamic State militants and the Ebola outbreak in West Africa.

In all, 52 percent of participants choose the Russia-Ukraine conflict as the greatest risk to global financial markets, while only 26 percent named the militants also known as ISIS. Ebola received 5 percent support, according to the poll. The poll of 510 Bloomberg subscribers was conducted last week by Iowa-based Selzer & Co. The poll has a margin of error of plus or minus 4 percentage points.

President Vladimir Putin said recently that falling oil prices could be potentially “catastrophic” for Russia, the world’s largest energy exporter. Venezuela, Saudi Arabia and Iran would also be hurt by a drop in crude prices, Bloomberg reported. The United States, China, Japan, Europe and India are poised to benefit most from cheaper oil.

Russia's economy has been strained by ongoing sanctions from the U.S. and Europe targeting its mighty oil markets over the ongoing conflict in Ukraine. Putin, meanwhile, warned Monday that he will continue to support separatists in eastern Ukraine as European Union ministers met to weigh new sanctions.

“You want the Ukrainian central authorities to annihilate everyone there, all of their political foes and opponents,” Putin said in an interview with ARD television in Germany. “Is that what you want? We certainly don’t. And we won’t let it happen.”

German Chancellor Angela Merkel has said the EU will continue sanctions against Russia “for as long as they are needed,” according to Business Week.

U.S. President Barack Obama accused Russia of providing weapons to the Ukraine separatists. “We’re also very firm on the need to uphold core international principles,” he said Sunday, “and one of those principles is you don’t invade other countries or finance proxies and support them in ways that break up a country that has mechanisms for democratic elections.”