Manafort didn't look good on CNN when he tried to challenge the NY TIMES story and the CNN reporter came right back at Manafort and reminded him that he once worked at the NYT and when a reporter/s had this kind of a story, they had to show management the details of their information (sources, etc.), or the story would not be printed.
I'm not familiar with a "foreign powers act" but if you're thinking of the War Powers Act, I'm not sure that would apply.
Interesting article in POLITICO...
TRUMP CHANGED VIEWS ON UKRAINE AFTER HIRING MANAFORT
Trump now says he might recognize Crimea as a Russian territory.
-POLITICO, August 3, 2016