Jon Hamm and Jennifer Westfeldt have finally decided to call it quits after spending 18 years together.

'Mad Men' star Jon Hamm and film maker Jennifer Westfeldt released a statement on Monday through their publicist Annett Wolf. It said that they were separating "with great sadness" after sharing nearly "18 years of love and history." It also mentioned that the couple, who decided to never marry would "continue to be supportive of each other in every way possible," People reported.

Jon Hamm and Jennifer Westfeldt had first met in 1997 and soon became "one of the Hollywood's most stalwart couples," The Guardian reported. They had even established a production company together, Point West Pictures, in 2009 and had even starred together in a 2011 film "Friends with Kids." The couple had stuck together even when Hamm's fame had skyrocketed during his years on "Mad Men."

In March 2015, it emerged that Jon had completed a course of rehab for alcoholism with his partner Westfeldt's support.

According to People, Jon Hamm and Jennifer Westfeldt were last seen together on July 22, 2015 at a premiere after-party in New York. The reports suggest that they were "canoodling" with each other.

"We may not have a piece of paper that says we're husband and wife, but after 10 years, Jennifer is more than just a girlfriend," Jon told People in 2012. He added, "What we have is much deeper and we both know that. To me, people [should] get married when they're ready to have kids, which I'm not ruling out."

Even Westfeldt had reciprocated her feelings for him. She compared living with Jon to living with a Beatle. She added that every second that she had spent with him was like an "OMIGODI'mgoingtodie!" moment.

But, lately a source told the US Magazine that they had finally split. He said, "They've been fighting for a while, but now they're done.

After ending their relationship, Jon Hamm and Jennifer Westfeldt have promised to be there for each other.