A Brooklyn man who suffocated his frail, 86-year-old mother with a pillow insists it was a mercy killing committed only after she told him “I don’t want to live anymore,” authorities said yesterday.

Yefim Tsirinsky, 52, called cops at 8 a.m. Friday, sources told The Post.

EMS technicians resuscitated Frida Tsirinsky in her home at West 12th Street and Neptune Avenue, but she died yesterday at Coney Island Hospital.

“My mother asked me to kill her,” said the son, who was charged with murder.