Thousands of flag-waving protesters chanted “We are Macedonians” at a rally in the Macedonian capital against a possible change to the name of the former Yugoslav republic to comply with a demand by Greece.

The protesters organised by the “We are Macedonia” movement gathered under a statue of the Hellenic ruler Alexander the Great in Skopje’s main square on Sunday.

Evica Stojanova-Kamberova, one of the organisers told the crowd: “We are here because questions about the name, the identity, the constitution [and] language are issues over which we must adopt a (strong) position.”

The small republic and its southern neighbour, Greece, have agreed to step up UN-brokered negotiations this year to solve a decades-old dispute that has hampered Skopje’s ambition to join Nato and the European Union.

Protesters demanded that the prime minister, Zoran Zaev, halt talks with Greece over the name dispute. They also want a UN resolution demanding recognition of the country under its constitutional name of Macedonia.

The protests were organised by the ‘We are Macedonia’ movement. Photograph: Georgi Licovski/EPA

They also accused the government and the main opposition nationalist party, VMRO-DPMNE, of betraying the national interest.

Greece objects to the country’s use of the name Macedonia, arguing it implies territorial claims over its own northern region of the same name.

After splitting from the former Yugoslavia in 1991, Macedonia was admitted into the UN in 1993 as the Former Yugoslav Republic of Macedonia (FYROM).

Last month, Zaev said Macedonia was looking at four options to settle the dispute with Greece that would include a geographical “qualifier” to ensure differentiation between the two names.

“The suggestions are Republic of North Macedonia, Republic of Upper Macedonia, Republic of Vardar Macedonia and Republic of Macedonia (Skopje),” Zaev said after a summit in London.

Asked whether he thought Greece would be happy with one of the options, he said: “Yes … They have more preferred options and some not so preferred options.”

Media reports showed parallel rallies staged by Macedonians living in foreign cities including Washington DC and Sydney, where the Greek flag and Zaev’s photo were set ablaze.