From February–June, 2016, Republican lobbyist Richard Burt lobbied for a natural gas pipeline owned by New European Pipeline AG, a firm controlled by the Russian government. This pipeline would enable Russian NG to reach Europe while bypassing Ukraine and Belarus. Source
It’s unclear, but this pipeline is potentially important to Russia’s motivations in Ukraine despite all the international sanctions. Plus, Burt had some level of involvement in the Mayflower Hotel meeting.