Mayor to Kardashians 'Here's the Key to Our City'

11/20/2012 5:30 AM PST

Mayor to Kardashians -- 'Here's the Key to Our City'

Kim, Kourtney and Khloe Kardashian received the keys to North Miami yesterday ... in a ceremony that reportedly started AN HOUR after it was supposed to ... because the girls were running late.

When they finally made it to the ceremony, Kim and Kourtney thanked the city for the honor ... and for allowing them to shoot their reality show in town.

North Miami Mayor Andre Pierre introduced the girls ... and remarked, "What can you say about the Kardashians that we don't already know? Three of the hardest working people in the business ... Khloe, Kim, and Kourtney ... we are honored by your presence."

Khloe was not at the ceremony -- she's in L.A. shooting "X Factor."

The Kardashians aren't the only celebs to have the key -- the honor is also shared by Wyclef and Disney star Adam Irigoyen.

11:50 AM PT -- Despite reports to the contrary, sources close to the K-sisters tell us ... Kim and Kourtney insist they were NOT late to the ceremony.

We're told the girls are adamant they were at the location at "noon sharp" ... and were hanging out with the mayor in his office.