Rudy Giuliani, a sometimes-cantankerous New York City mayor, has often traveled to Russia or other former Soviet states as guests of powerful players there. And since Trump was elected, he appears to have stepped up the frequency of those trips.
Just last week, for example, Giuliani appeared in the former Soviet republic of Armenia, which has close trade ties with Russia. He was invited, according to local press accounts, by Ara Abramyan, an Armenian businessman who lives in Russia. Abramyan once helped reconstruct the Kremlin and also received a medal for "merit to the fatherland" from President Vladimir Putin of Russia. Giuliani said he was in Armenia as a private citizen, but on a local TV news show, Abramyan implied that he expected Giuliani to carry a message for him to Trump, according to ProPublica.
While in Armenia, Giuliani also attended a technology conference (one of his businesses advises on cybersecurity). The conference program listed him as appearing on a panel that also included a Russian currently on the U.S. sanctions list imposed after Russia's invasion of Crimea.
Giuliani's work abroad does not appear to break any laws or rules. But it also appears to be unprecedented.