SKOPJE, Macedonia (AP) — German chancellor Angela Merkel visited Macedonia Saturday, the third western leader to do so this week in a show of support for the government ahead of an upcoming referendum to change the country's name and qualify for NATO membership.

Macedonians vote Sept. 30 on a proposal to change the former Yugoslav republic's name to "North Macedonia." The name change would end a long-running dispute with neighbor and NATO member Greece, which has accused the Balkan nation of implying a claim to its territory and ancient heritage of its own northern region of Macedonia.

"This is a historic chance that a generation has only once. Don't stay at home: Seize the democratic opportunity to say what you think about the future of your country," Merkel said at a joint news conference with Macedonian Prime Minister Zoran Zaev.

The agreement between Greece and Macedonia was signed in June at Lake Prespa on the border of the two countries. It requires the approval in a referendum and a change to Macedonia's constitution.

The German chancellor visited after Austrian Chancellor Sebastian Kurz and NATO Secretary General Jens Stoltenberg both made trips to Skopje to back a "yes" vote in the referendum.

U.S. President Donald Trump, in a written message to his Macedonian counterpart Gjorge Ivanov on Thursday, said: "The Agreement and Macedonia's membership in NATO will bolster security, stability, and prosperity throughout the entire region."

Polls indicate that Macedonians will back the deal, but it remains unclear whether turnout will meet the required 50 percent threshold.

Conservative opposition parties in Macedonia and Greece both remain firmly opposed to the agreement. Protests against the deal are expected later on Saturday in the northern Greek city of Thessaloniki.