A senior U.S official says Macedonia could join NATO by early 2020 if it implements an agreement with Greece to rename itself North Macedonia, resolving the two countries’ decades-old name dispute, AP reported.

U.S. Deputy Assistant Secretary of State Matthew Palmer said Tuesday in Sarajevo that Macedonia could become the 30th member of NATO “as early as in 18 months from now.”

“That is an entirely realistic target date,” he said.

However, Palmer voiced concern over Russian “malign influence” in the Western Balkans, including efforts to undermine Macedonia’s decision to pursue NATO membership.

“The Kremlin sees its interests in the region as being advanced through friction, distrust, disorder,” Palmer said, adding that Russia was primarily focused on advancing its “visions and goals which are increasingly at odds with our own.”