Rubin served as Deputy Chief of Mission at the US Embassy in Moscow from 2008 to 2011, according to the release. He also served in other notable positions dating back to the mid-1990s, including as Assistant White House Press Secretary for Foreign Affairs and Deputy Political Counselor at the US Embassy in Kiev.
Scott has served as a Senior Fellow at the German Marshall Fund since 2014, the release noted, was Director of the US Office of Russian Affairs from 2009 to 2011 and US Deputy Chief of Mission to the Organization for Security and Cooperation in Europe (OSCE) from 2005 to 2009, among other roles.
The announcement of the Bulgarian ambassadorship comes amid growing tensions between Russia and Bulgaria over Sofia’s decision last week to close its airspace to Russian transport planes carrying humanitarian aid to Syria.
Bulgaria's decision to deny its airspace to Russian aid flights to Syria comes after a similar request was allegedly made by the United States to Greece.
In June, Serbian Prime Minister Aleksandar Vucic said his country had no intentions of joining NATO, citing the US-led alliance’s 1999 bombing campaign of Serbia as cautionary tale.
On Tuesday, Vice President Joe Biden told Vucic that the United States will consider providing additional aid to help the country deal with the current migrant crisis that is affecting Europe.
Biden and Vucic also discussed Serbia’s process of integration in the European Union, its implementation of economic reforms as well as energy security.