Liverpool is breaking the world transfer record for a defender by signing Virgil van Dijk from Southampton in a $100 million move.

Following Liverpool's long-running pursuit of the 26-year-old Netherlands centre back, Southampton announced on Wednesday that it accepted the record fee ahead of the January transfer window opening.

"Delighted and honored to have agreed to become a Liverpool FC player," Van Dijk wrote on Instagram alongside a picture holding a jersey of the club he will join on January 1. "Today is a proud day for me and my family as I join one of the biggest clubs in world football!

"I can't wait to pull on the famous red shirt for the first time in front of the Kop and will give everything I have to try and help this great club achieve something special in the years to come."

The transfer fee of 70 million pounds ($94 million) could reach 75 million pounds ($100 million) depending on Van Dijk's achievements at Liverpool.

The scale of the investment signals Liverpool's determination to plug leaks in the defense that have seen the team fall 17 points behind leader Manchester City into fourth place in the English Premier League.

Liverpool is devastating going forward, with the "Fab Four" attack of Philippe Coutinho, Roberto Firmino, Sadio Mane and Mohamed Salah helping the team amass a 46-goal haul that only City has eclipsed.

But Juergen Klopp's team has conceded 23 goals in 20 games — more than any rival in the top five — including three in last week's 3-3 draw at Arsenal after a two-goal lead was thrown away.

The Van Dijk deal eclipses the previous highest amounts paid for defenders who are rarely in contention for the top awards in football dominated by goal-scorers. English Premier League leader Manchester City paid around 50 million pounds each for Benjamin Mendy and Kyle Walker in the summer transfer window.

While Van Dijk becomes the world's most expensive defender, Neymar still holds the title of the game's costliest player after joining Paris Saint-Germain from Barcelona for 222 million euros in August.

"There is a dearth of top-class center backs throughout world football hence why so many clubs wanted (Van Dijk) and the transfer fee is so high," former Liverpool center back Jamie Carragher told broadcaster Sky Sports. "People will look at the transfer (fee) that normally strikers go for, but as with any transfer fee if he performs well and does his job it will be worth it."

That, according to Carragher, will require Van Dijk helping the 18-time English champions end a trophy drought that stretches back to the 2012 League Cup.

Van Dijk hoped to join Liverpool in August after handing in a transfer request but Southampton stood its ground and forced the Anfield club to apologize for its conduct in pursuing a deal.

Van Dijk, though, will become the sixth player to leave Southampton for Liverpool in less than four years when the transfer is completed next week.

"I will always be indebted to the club for giving me the opportunity to play in the Premier League and despite a difficult last few months I have thoroughly enjoyed my time at Saints and have made friends for life at the club," said Van Dijk, who joined Southampton from Celtic in 2015 for a reported 13 million pounds.

Van Dijk is joining a team fighting on three fronts. The FA Cup campaign opens next week with a Merseyside derby against Everton, and the Champions League resumes in February with a last-16 meeting with Porto.