The "Jesus Walks" rapper stunned fans earlier this year, by praising Trump, who has been accused of racism, corruption and misogyny, on Twitter before travelling to The White House for a bizarre televised meeting with America's leader.
Kanye was supposed to debut his now delayed new record, "Yandhi", in September, shortly before the summit - and the "I Try" hitmaker, 51, suspects the hip-hop star's entry into politics is all a publicity stunt.
"People are welcome to support who they want," she told U.K. breakfast show "Good Morning Britain". "My thing is he only supports him when his album is coming out. I just think it's not real, every time he has an album coming out he decides to support Trump."
The hip-hop star also met with Trump the month after his November 2016 election victory. Kanye did not have a record coming out at the time as he had recently cancelled his Saint Pablo Tour after being hospitalised for stress and exhaustion. Following backlash from fans, last month, the 41-year-old tweeted he was "distancing" himself from politics as he felt "used".
In her interview Macy said she's never been a huge fan of her country's controversial leader - but that his recent Twitter comment falsely blaming wildfires in California on local government officials and threatening to cut off their funding was a step too far.
"I wasn't a fan but he really lost me on his comment on the fires," she explained. "When people are losing their homes and losing their family members and all he can talk about is funding and cutting the forest administration. I think, as a person, he doesn't get it. You don't have to be President to know to say that. So, he really lost me with that one."
Kanye and his wife Kim Kardashian nearly lost their home to the inferno - reportedly hiring their own fire crew to keep the flames away from their $60 million (£46 million) mansion.
"Yandhi"'s release date was initially pushed back to November 23, but Kanye has now pulled the album indefinitely while he finishes it.