Running back Jamaal Charles reached an agreement on a contract extension with the Kansas City Chiefs on Wednesday as the team reported for training camp.

The team confirmed that Charles signed, though it didn't announce the terms. According to media reports, Charles landed a two-year, $18 million extension that runs through 2017. His salary over the next two years reportedly goes up by $5.1 million.

The Kansas City Star reported that Charles' $8.3 million salary for 2014 will be the second-highest among running backs, trailing only the Minnesota Vikings' Adrian Peterson, who will make $11.75 million.

"Jamaal is an elite player in the National Football League," Chiefs general manager John Dorsey said in a statement. "It was important for us to keep him here in Kansas City long-term."

Charles was not at the Chiefs' training camp at Missouri Western State University when the players reported Wednesday afternoon but was headed there after the deal was struck.

He joked on his Twitter account, "I had no intention on holding out...I just ran out of gas on the way to camp and my cell phone battery died. It was a long walk I tell ya."

Earlier Wednesday, it was reported that Charles intended to hold out for more money rather than join the team for full-squad practices Thursday.

According to multiple reports, Charles was unhappy with his 2014 salary of $3.7 million, the fourth year of a six-year, $27.97 million deal signed in 2010.

Charles, 28, rushed for 1,287 yards in 2013, which was the third-best total in the NFL last season, and he ran for 1,509 yards in 2012. He made his third Pro Bowl after the 2013 season, and he was selected first-team All-Pro for the second time.

However, 10 other NFL running backs had a higher base salary than Charles before he reached the new agreement Wednesday.