Greek Prime Minister Alexis Tsipras delivers a televised address to announce that Athens and Skopje have reached a historic agreement on their name row, in Athens, Greece, June 12, 2018. Severna Macedonja (Republic of North Macedonia in English) will be the new name of Former Yugoslav Republic of Macedonia (FYROM) under a historic agreement reached between Greece and the neighboring state, Greek Prime Minister Alexis Tsipras said in Athens on Tuesday. (Xinhua/Marios Lolos)

ATHENS, June 12 (Xinhua) -- Greek Prime Minister Alexis Tsipras on Tuesday hailed as a historic opportunity the agreement reached with the Former Yugoslav Republic of Macedonia (FYROM) to resolve the decades-old name row between the two neighboring countries.

Severna Macedonja (Republic of North Macedonia in English) will be FYROM's new name, he announced during a state address broadcast live on Greek national broadcaster ERT, as his FYROM counterpart Zoran Zaev was making similar public statements at Skopje.

"I deeply believe that this agreement represents a major diplomatic victory, as well as a great historic opportunity... This is a historic moment for the Balkans, for our nations," the Greek leader said.

According to the outline of the deal clinched between the two governments on Tuesday after a final telephone conversation with Zaev, as presented by Tsipras, the new name will be used erga omnes, meaning both internationally and domestically.

Skopje agreed to proceed to a constitutional amendment to remove references which have been perceived as "irredentist" by Greece, according to the Greek leader.

The name dispute started in 1991 when FYROM declared independence from Yugoslavia and chose the name Macedonia, which is also the name of a northern Greek province.

Athens expressed concern from the beginning that the use of the same name by the neighboring state could lead to territorial claims.

UN-mandated marathon negotiations remained fruitless for years, but in past few months both government appeared determined to end the row this June and clear the way for FYROM to join the EU and NATO ahead of a critical EU summit later this month.

Tsipras stressed that should the constitutional changes at Skopje do not end positively, the neighboring state will see any invitation for talks with EU and NATO cancelled.

"It is clear that the responsibility for whether our neighboring country means to observe the terms we have set or not lies with it," Greek President Prokopis Pavlopoulos told Tsipras on camera when the latter briefed him at the presidential mansion shortly before the state address.

On Tuesday evening, Tsipras also formally briefed the leaders of opposition parties, as the government seeks a wide majority in parliament when the deal will reach the assembly. According to Greek government sources, it will happen most likely in autumn after the referendum Zaev called at Skopje.

Despite the determination of the two leaders, all proposed resolutions so far have been rejected by hardliners in both countries.

The Greek prime minister can not count on the right- wing Independent Greeks (ANEL) party which is the junior partner in the two-party coalition government.

Earlier on Tuesday Greek Defense Minister and ANEL leader Panos Kammenos voiced doubt whether the draft agreement with Skopje could be reached and rarified by the parliaments.

The party had expressed objection to the use of the term Macedonia in any composite new name for the neighboring state several months ago.

"When the time comes and the name issue will be put to vote, we will remain loyal to what we promised Greek people," Kammenos said during a press briefing at his party's headquarters, referring to the approval procedures of any deal in the Greek parliament.

"I believe we will not even reach this point and hold a vote in parliament, because I think the other side will not be able to have the agreement ratified," he added.

Regardless of ANEL's stance, Greek media commentators commented on Tuesday that the agreement may be supported by opposition parties or independent MPs.

Without ANEL, the Radical Left SYRIZA party of Tsipras holds 145 seats in the 300-member strong parliament.