Kopac extended a letter of congratulations to Yuri Prodan, approved Thursday as Ukraine's new energy minister.
"I am extremely happy with the appointment of a new government in Ukraine and its reform-oriented program," Kopac said in a statement Thursday. "They have many challenging tasks ahead of them."
Ukrainian Prime Minister Arseniy Yatseniuk called on Prodan to obtain information on Ukraine's gas debt to Russia and provide estimates of how much natural gas Russia was sending through the Soviet-era transit system in Ukraine, the Interfax news agency reported Thursday.
Last week, the European Energy Community, bound by a 2006 treaty to look for a common regulatory energy framework, said energy policy is a "crucial" element of economic and social stability in Ukraine.
Protesters in Ukraine, a former Soviet republic, expressed frustration in November when the government suspended efforts to sign free trade and association agreements with the European Union to protect its economic ties with Russia.
Ousted President Viktor Yanukovych, a Kremlin ally, fled Ukraine this month.
The European Union relies on Russia for about a quarter of its natural gas supplies and most of that runs through the Soviet-era pipeline network in Ukraine.