Camouflage-clad Russian soldiers parachute from the sky, armored vehicles fire live rounds on an open field after being dropped from military transport jets and helicopters fire missiles against enemy positions.

Although the flat terrain resembles the Ukrainian war zones, this is not an armed Russian intervention against its neighbor. It's the first-ever joint Serb-Russian military exercise in Serbia, the Balkan country that has been performing a delicate balancing act in between its Slavic ally Russia and Western Europe, with which Belgrade wants to integrate.

The "anti-terrorist' drill on Friday — the first such by the Russians outside the former Soviet Union — of elite Russian troops in northern Serbia, not far from NATO-member Croatia, has stirred controversy both here and abroad.

"Serbia's government wants to try and keep everyone happy," said prominent Balkan political analyst Tim Judah. "So, the U.S. helps finance and modernize Serbia's army while now Serbian soldiers train with Russians. In normal times there would be little to say about this, but post-Crimea, these are not normal times anymore."

Although Serbian officials say they respect Ukraine's territorial integrity and do not support Russia's annexation of Crimea, they have refused to impose sanctions against Russia like the EU and the U.S. have. Russia and Serbia have traditionally close historic and cultural ties, and Moscow has backed Belgrade's bid to maintain its claim over Kosovo — a former Serbian province that declared independence in 2008 with the support of Washington and its allies.

The show of Russian military might in a country seeking to join the European Union comes as Russia, blamed by the West for fomenting the Ukraine crisis, tries to increase the Kremlin's presence in the Balkans.

"During our short stay in Serbia, we established the basis for expanding of our military relations," said Russian Gen. Vladimir Shamatov.

Russian President Vladimir Putin was in Belgrade last month where he received a hero's welcome that included a Soviet-style military parade. The head of the Russian Orthodox Church, Patriarch Kirill, arrived in Belgrade on Friday.

"Serbia says it supports the territorial integrity of Ukraine, yet it welcomes Putin with a military parade and its soldiers are training with the army that annexed Crimea and is fighting in Ukraine," Judah said. "As the (Ukrainian) war goes on this is an increasingly untenable position and Serbia's government will just annoy both Russia and its Western friends rather than being on good terms with all."

Serbian Defense Minister Bratislav Gasic said he believes Serbian "neutrality" is tenable and defended holding the drill with the Russians.

"There are no secrets about this exercise," he said after the drills that included a mock live-ammunition attack against a terrorist base with armored vehicles and about 200 troops, some deployed by Ilyushin IL-76 transport aircraft.

"We are militarily neutral and we would like to maintain good relations with everyone, including Russia, the European Union, the United States and China," Gasic said, adding that Serbia — which has never been part of any Russian or Western military alliance — will also hold military drills with the Americans next month in Serbia.