Bulgaria, in a move aimed to reduce dependence on Russia, is working toward signing a contract with Poland to service the country's Soviet-era MiG-29 fighter jets, Defense Minister Nikolay Nenchev said, according to a Reuters report. Increased tensions between the West and the Kremlin prompted Bulgaria to seek a new contract for its jets, which had previously been maintained by Russia.

The United States and other Western leaders have had a tense relationship with Russia over the conflict in Ukraine between pro-Russia separatists and the Ukrainian government. The West has suggested Russia has been involved in the conflict, while the Kremlin has repeatedly denied any direct role. Bulgaria, a member of NATO, is reportedly seeking to ease its dependence on the Russia and switching to Poland for its jet services is just one step in the process.

"We will do everything possible to reduce our dependence on Russia," Nenchev said Monday, according to Reuters. "Bulgaria is the only NATO member that is almost 90 percent dependent on Russia. It worries me very much, and I would not like to continue in this way."

Bulgaria was "once in Moscow's orbit," especially concerning military, energy and trade relations, according to Reuters. Now it is seeking a contract with Poland to repair its aging fleet of MiG-29 jets, with its contract with Russia set to expire in September.

"We need to repair six of our engines and we have made serious efforts to find an alternative," Nenchev said. "We held very dynamic talks with the Polish side for several months and I think we could sign a contract this month."

Tensions among neighboring states have risen amid Russia's annexation of Crimea and the conflict in Ukraine. Earlier this year, NATO set up command centers in six eastern European nations -- Poland, Romania, Bulgaria, Latvia, Lithuania and Estonia.

"I do not hesitate to say it. After seeing that the Putin regime had a particularly aggressive behavior to a sovereign state, we cannot feel secure," Nenchev said.

Bulgaria and the United States have staged a number of joint military drills since the Ukraine crisis began with more than 70 such drills planned in 2015. The Pentagon said in June it would station 250 pieces of heavy weaponry, including tanks, howitzers and armored vehicles, in the six eastern European nations with command outposts. That news came after NATO said it planned to increase its number of rapid response troops from 30,000 to 40,000 troops, according to an Agence France-Presse report.