6:56 PM PT -- Kim Kardashian has issued a statement on her meeting with Trump, saying ... "I would like to thank President Trump for his time this afternoon. It is our hope that the President will grant clemency to Ms. Alice Marie Johnson who is serving a life sentence for a first-time, non-violent drug offense. We are optimistic about Ms. Johnson’s future and hopeful that she—and so many like her—will get a second chance at life."

3:31 PM PT -- Our sources say the meeting with Trump went "extremely well." We're told Kim and Shawn will now meet with Jared Kushner -- who's been very passionate and hands-on with Alice's possible pardon and criminal justice reform -- and Ivanka at their home for a private dinner.

Before she left the Oval Office, Kim posed for a pic with 45, which he posted. One of them smiled ...

Kim Kardashian West is all business, in a pantsuit, as she arrives at the White House to meet President Trump.

Kim and her attorney, Shawn Holley, entered through the security gate for the West Wing of 1600 Penn ... around 4:40 PM EDT. As we reported, the meeting with POTUS has been in the works for months ... as KKW's been in talks with Ivanka Trump and Jared Kushner to get Alice Marie Johnson's life sentence commuted.

Alice is the great-grandmother who was convicted for drug conspiracy and money laundering in 1997 ... they were her first offenses, and Kim's taken up her cause over the last year.

Her attire -- all black, besides yellow heels -- shows just how serious Kim is about her mission.