North Macedonia's first woman president was inaugurated on Sunday, with the new nationalist leader angering Greece after a speech that did not acknowledge her country's new name.
The Balkan nation added "North" to its title in 2018 to end a long-running dispute with Greece, following an historic agreement.
But Gordana Siljanovska-Davkova's party, the nationalist VMRO-DPMNE, opposed the accord and has refused to acknowledge the country's new name.
The right-wing party earned an easy victory in parliamentary and presidential elections on Wednesday, with the ruling Social Democrats (SDSM) conceding defeat before any official results were announced.
Addressing lawmakers and assembled invited VIPs on Sunday, Siljanovska-Davkova said she would "respect the constitution and the laws and shall protect the sovereignty, territorial integrity and independence of Macedonia".
"I declare I shall carry out the office of president of Macedonia in a conscientious and responsible manner," she added.
The official written text of her address included the official name North Macedonia, an AFP reporter saw.
Siljanovska-Davkova, who turned 71 on Saturday, was elected as president to a five-year mandate after securing a second-round poll victory with 65 percent of the vote.
She defeated Social Democratic outgoing head of state Stevo Pendarovski, who gathered 29 percent.
The retired university professor vowed to be the president of "all citizens".
Skopje's 2018 Prespa Agreement with Athens to add the prefix North to its name ended decades of quarrelling with Greece, which was opposed to its neighbour bearing the same name as that of one of its historic provinces.
The issue had seen Greece long oppose the country joining NATO -- it did finally join the alliance in 2020 -- and delay talks on its path to eventually becoming an EU member.
But Greece reacted angrily to the new president's speech, saying her choice of words was "a blatant violation" of their agreement.
"Greece categorically declares that further progress in its bilateral relations with North Macedonia, and its European journey, depends on the full implementation of the Prespa Agreement and above all, on the use of the constitutional name," the foreign ministry added.
Greece's ambassador to Skopje left the ceremony at the parliament in protest, according to local media reports.
European Commission president Ursula von der Leyen and European Council chief Charles Michel both offered Siljanovska-Davkova congratulations.
But von der Leyen added on X, formerly Twitter, that North Macedonia must keep to "the path of reforms and full respect for its binding agreements, including the Prespa Agreement", to continue its EU accession journey.
VMRO-DMPNE also topped the May 8 legislative polls, winning 58 of 120 parliamentary seats to see off the SDSM, in power since 2017.
The return to power of the right in the poor country of 1.8 million risks reigniting tensions with Greece as well as Bulgaria, which has placed its own conditions for North Macedonia being afforded EU membership.
Sofia has long blocked accession for Skopje over linguistic and historical issues.
