Macedonia has accused neighboring Albania of interfering in its domestic affairs, saying that Tirana is trying to influence the Balkan country's ethnic Albanian minority.
The Macedonian Foreign Ministry said on April 4 that Skopje had summoned Albania's ambassador to protest what it called Albania's "open interference in Macedonia's internal affairs."
It accused Albania of trying to "change the constitutional order in Macedonia."
Macedonia is mired in a political deadlock, with parties representing the ethnic Albanian minority -- which makes up about 25 percent of its 2.1 million population -- demanding concessions to join any coalition following December parliamentary elections.
After meetings in Tirana under the sponsorship of Albanian Prime Minister Edi Rama, Macedonia's main ethnic Albanian parties agreed on a platform of demands, seeking more rights and the establishment of Albanian as Macedonia's official second language.
Following the elections, nationalist VMRO-DPMNE leader and former Prime Minister Nikola Gruevski was unable to build a governing coalition because he refused the language demands.
Social Democratic Union leader Zoran Zaev agreed with the language demands and attempted to form a coalition with the ethnic Albanian parties.
But President Gjorge Ivanov, also from the VMRO-DPMNE, has refused to give Zaev the official mandate to do so.
Ivanov argued that the language issue was an attempt to destroy Macedonia's independence, and he has accused Albania of interference in its domestic affairs.
In its statement of April 4, the Macedonian Foreign Ministry said it warned Ambassador Fatos Reka against a "serious provocation to good neighborly relations that we wish to maintain."
Albanian Foreign Minister Ditmir Bushati on April 3 criticized the move by "Gruevski and his political group to transform a democratic crisis into an ethnic crisis."
European Union President Donald Tusk visited Skopje on April 3, but he failed to resolve the crisis.
"My position remains unchanged," Ivanov said after Tusk's visit.
With reporting by AFP and European Western Balkans