"We are entering a period of transition in our relationship which is a difficult but constructive process," Robert De Niro says of split from wife Grace Hightower

Robert De Niro has split from his wife, Grace Hightower, after more than 20 years of marriage.

The Oscar winner released a statement about the separation a week after PEOPLE confirmed the two were going their separate ways.

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“Grace and I have two beautiful children together. We are entering a period of transition in our relationship which is a difficult but constructive process,” the statement read. “I honor Grace as a wonderful mother and ask for privacy and respect from all as we proceed to develop our roles as partners in parenting.”

The Wizard of Lies actor, 75, married Hightower, 63, in 1997 after dating for a decade. They share two children together: 20-year-old son Elliott and 6-year-old daughter Helen Grace.

This isn’t the first time the two have separated. De Niro filed for divorce in 1999 and engaged into a custody dispute over their son. The pair eventually smoothed things over and the divorce was never finalized.

In November 2004, the two renewed their vows in front of an A-list crowd such as Martin Scorsese, Meryl Streep, Ben Stiller, Tom Brokaw and others.

Image zoom De Niro and Hightower at the Tony Awards in New York City Kevin Mazur/Getty

At the time, the Raging Bull actor jokingly referred to their previous marital problems saying he wanted to “make sure this one sticks.”

The two were last seen on the red carpet in June when they attended the 72nd Annual Tony Awards in New York City. While De Niro has kept his private life out of the spotlight he did show his softer side while speaking about his family.

“There are great moments and moments of sadness,” he previously told PEOPLE of raising his kids. “Sometimes you’re the last person they want to deal with. It’s like when you walk your kids to school and they get older and they don’t want to hold your hand or kiss you goodbye.”

De Niro also has four other children: daughter Drena, 47, and son Raphael, 42 with former wife Diahnne Abbott, as well as 23-year-old twin sons Julian and Aaron, with ex-girlfriend Toukie Smith.