Here is more from the New York Times:
In the weeks before Ukrainian President Volodymyr Zelensky was elected in April, his advisers quietly worked with a Washington lobbying firm, Signal Group, to arrange meetings in Washington with Trump administration officials, as well as congressional offices and think tanks that focus on Ukraine-United States relations.
Ms. Heather Conley, who is director of the Europe program at the Center for Strategic and International Studies, was among the think tank officials who met with one Mr. Zelensky’s advisers in April in a meeting arranged by Signal and Mr. Marcus Cohen.
They discussed Mr. Zelensky’s anticorruption and economic overhaul plans, Ms. Conley said, adding, “Ukraine faces a fraught landscape in Washington — with or without a lobbyist.”
A number of think tanks are deeply involved in US-Ukraine affairs. In 2019, a group of 10 think tanks held an event on US strategic interests in Ukraine that included CSIS, Atlantic Council, American Enterprise Institute (AEI), American Foreign Policy Council (AFPC), Brookings Institution, Carnegie Endowment for International Peace, Heritage Foundation, Center for European Policy Analysis (CEPA), German Marshall Fund (GMF), and Jamestown Foundation.