BELGRADE, Serbia — Ukrainian President Petro Poroshenko met Tuesday with his Serbian counterpart in a bid to boost ties with the Balkan country, a key Russian ally in Europe, as both states seek to join the European Union.

The two countries' delegations signed bilateral deals and predicted better ties in the future.

Serbia has not joined Western sanctions imposed against Russia over its 2014 annexation of the Crimean Peninsula from Ukraine. Serbian volunteers have also fought alongside pro-Russian separatists in Ukraine.

But both Poroshenko and Serbian President Aleksandar Vucic said their countries respect each other's territorial integrity and want to cooperate in both countries' efforts at EU membership.

Vucic said that "Ukraine supports the territorial integrity of Serbia, the same way Serbia supports the territorial integrity of Ukraine."

"Serbia and Ukraine have no open bilateral issues and consider each other as exceptionally friendly nations," Vucic said.

Poroshenko added that "we in Kiev are making all the efforts to restore Ukrainian sovereignty at all occupied territories."

Referring to Serbia's territorial dispute with Kosovo, which declared independence in 2008 despite Serbian opposition, Poroshenko urged a solution that is acceptable to both sides.

"We have not recognized Kosovo and our position is that the Kosovo problem should be solved in a compromise that would respect the interests of Serbia," he said in comments translated into Serbian by an official interpreter.

Serbia and Kosovo must solve their dispute that stems from the breakup of the former Yugoslavia in the 1990s, to advance toward EU membership. Serbia has relied on Russia's backing in its bid to maintain claim on the territory.

Poroshenko and Vucic earlier this month attended in Turkey the inauguration of a key pipeline carrying natural gas from Azerbaijan's gas fields to Turkish markets and eventually to Europe, part of a wider Southern Gas Corridor project that aims to diversify gas supplies and reduce countries' dependence on Russia.