U.S. Soccer has hired a law firm to oversee an investigation of manager Gregg Berhalter over details surrounding an altercation that occurred in 1991, the federation announced Tuesday.

Berhalter, whose contract expired on Dec. 31 according to an ESPN source, released a statement of his own Tuesday, saying someone had contacted U.S. Soccer with information that would "take him down" and revealing that he had kicked his longtime partner, Rosalind, following a barroom argument while in college at the University of North Carolina.

"In the fall of 1991, I met my soulmate. I had just turned 18 and was a freshman in college when I met Rosalind," Berhalter wrote on Twitter. "One night, while out drinking at a local bar, Rosalind and I had a heated argument that continued outside. It became physical and I kicked her in the legs."

Berhalter said the authorities were never involved and that he sought counseling after the incident. The two reconciled after the fight, got married and have four children.

"The lessons learned from that night over three decades ago became the foundation for a loving, devoted, and supportive relationship, which we honored and celebrated with our 25th wedding anniversary this past weekend," Berhalter added.

Regarding the investigation, U.S. Soccer said in its statement: "Upon learning of the allegation against U.S. Men's National Team head coach Gregg Berhalter on Dec. 11, 2022, U.S. Soccer immediately hired Alston and Bird LLP to conduct an independent investigation into the matter.

"Through this process, U.S. Soccer has learned about potential inappropriate behavior towards multiple members of our staff by individuals outside of our organization. We take such behavior seriously and have expanded our investigation to include those allegations."

U.S. Soccer added that a full technical review of the men's program was also ongoing and that it would announce who will lead the squad for an upcoming January camp and subsequent pair of friendlies in the coming days.

The federation also thanked Berhalter and his wife for coming forward to speak about the incident, while adding that it condemns violence of any kind and takes such allegations very seriously.

Berhalter, 51, was hired in December 2018 after the U.S. failed to qualify for that year's World Cup. He has led the team to 37 wins, 11 losses and 12 draws, and the Americans earned the third and final automatic World Cup berth from CONCACAF for the 2022 tournament.

Berhalter is the first American to play for and coach the U.S. at a World Cup, where he led the USMNT to second place in Group B in Qatar before losing 3-1 to the Netherlands in the round of 16.