James Harden and the Houston Rockets have agreed a four-year contract extension which ties the All-Star to the franchise through the 2022-23 season.

The Rockets guard's new deal with the organisation was announced by team owner Leslie Alexander on Saturday.

According to ESPN, the supermaximum deal is worth a whopping $228million and is the largest contract extension in NBA history. 

"Houston is home for me," Harden said. "Mr. Alexander has shown he is fully committed to winning and my team-mates and I are going to keep putting in the work to get better and compete for the title."

Previously, Golden State Warriors star Stephen Curry had the biggest contract extension after he recently signed a four-year deal worth $201m.

Once the extension starts in 2019, Harden will start earning $37.8m, with his annual salary going up to $40.8m, $43.8m and $46.8m over the next three seasons.

Harden has earned his huge deal - he averaged 29.1 points, 11.2 assists and 8.1 rebounds per game while helping the Rockets secure the third seed in the NBA playoffs last season, ultimately coming second to Russell Westbrook in the MVP voting.

Houston, who had a 55-27 record last season, have also made the playoffs in each of the five years Harden has been on the team.

Harden's new team-mate Chris Paul was among the NBA stars to congratulate him on Twitter, with reports suggesting the Rockets will now push hard to trade for New York Knicks All-Star Carmelo Anthony.