© Radio Slobodna Evropa (RFE/RL)Signs in Macedonia urging people to either vote for the referendum or boycott it altogether
Mattis told reporters on September 11 that the visit will occur this weekend and is aimed at supporting the Macedonian voters in the September 30 referendum. If the referendum passes, it would help pave the way for membership in NATO and the European Union.
"I am concerned about...the kind of mischief that Russia has practiced from Estonia to the United States, from Ukraine and now to Macedonia," Mattis said, according to a Pentagon transcript.
This visit, Mattis said, "is in support of their decision -- their own sovereign decision to make sure that they know that we believe it should be our Macedonian friends charting their country's future, and not outsiders."
The referendum is aimed at getting voters' approval for a deal Macedonia signed with Greece in June. The deal changes Macedonia's name to the Republic of North Macedonia, ending a dispute with Greece that has lasted for decades.
Nationalists in both countries have opposed the deal.
If the deal is approved, and Macedonia's constitution is changed, it will open the door for Macedonia to join the EU, and also NATO, something that Russia has publicly opposed.
Russia's ambassador to Skopje has warned that Macedonia could become "a legitimate target" if relations between NATO and Russia deteriorate further.
Greece has seen nationalist demonstrations in opposition of the deal. But in June, Athens expelled two Russian diplomats, accusing them of having helped encourage the protests and also bribing unidentified officials to undermine the deal.
Macedonia has seen a steady stream of U.S. and European officials traveling to the country, encouraging voters to turn out and cast their ballots -- and in support of the name change.
U.S. Senator Ron Johnson, who sits on a Senate subcommittee overseeing European and regional security, traveled to Skopje on September 9, where he urged Macedonians to "get out and vote."
NATO Secretary-General Jens Stoltenberg, Austrian Chancellor Sebastian Kurz, and German Chancellor Angela Merkel have also visited.
Comment: The Macedonians apparently don't know what's in their own best interest, so they need to be told what to do by Mattis and other outside influences that have a track record of being completely impartial, unbiased, and benevolent.