The Vikings have reached an impasse in negotiations on a new contract for running back Dalvin Cook, after talks broke off between the team and Cook's agent Wednesday.

Cook continued to participate in practice, splitting first-team snaps with Alexander Mattison during 11-on-11 drills.

Cook, 25, said last week in a videoconference that he would be "full-go" in training camp, even without a new deal, and that his focus was on getting ready for the season.

The latest development in a fraught set of negotiations, however, comes with less than four weeks before the Vikings are scheduled to open the season at home against the Packers on Sept. 13.

Sources with knowledge of the situation said the Vikings met with Cook's agent, Zac Hiller, in Minnesota over the weekend, and the team expected a response to its offer by Tuesday. With the team and Cook's camp still unable to agree on a deal, things officially came to a halt Wednesday.

During Rick Spielman's time as general manager, the Vikings have built their roster on the principle of developing and re-signing draft picks, and Spielman said at the combine that the team intended to make Cook its next recipient of a long-term contract sometime this summer.

Sources said the Vikings' offer has remained in the same range through the spring and summer; at various points during the negotiations, the team seemed optimistic a deal was close.

The cessation of talks Wednesday, though, came with the sides unable to find a way past familiar sticking points. It's believed Cook would agree to a contract averaging around $13 million per season, similar to the contracts David Johnson signed with the Cardinals in 2018 and Le'Veon Bell signed with the Jets in 2019. This summer, the Titans gave Derrick Henry — who is 19 months older than Cook — a four-year deal that averages $12.5 million per season.

The Vikings have slowly increased Cook's workload over the past two days, after effectively holding him out of team drills during their first three days of practice.

He could see a larger set of work in training camp with negotiations stalled, though it remains to be seen if Cook's declaration about his focus being on Week 1 means he will take the field without a new contract.

Cook, who missed games because of injuries in each of his first three seasons, said last week he has not taken out an insurance policy to guard against injury without a new contract.

"I think I'm an insurance policy, me, myself," he added. "I'm ready to go. I'm ready to play football. Injuries come with the game, and it's just how you deal with them.

"There never was an injury I couldn't battle back from, and it just comes with it. You've got to accept that. I've put myself, my body, in the best position to succeed this whole season."

The running back skipped the final days of the Vikings' offseason program with the sides unable to reach a deal in June, but showed up for the start of training camp on July 27. Rules in the NFL's new collective bargaining agreement would have prevented Cook from becoming a free agent at the end of the 2020 season if he had not reported to camp on time.

Cook became a Pro Bowler last season after posting 1,135 rushing yards and another 519 receiving yards, despite playing through shoulder injuries that limited him in the final weeks of the regular season. His 1,654 yards from scrimmage were the 10th most by a Vikings player in a single season. Cook posted 130 yards from scrimmage and two touchdowns in the Vikings' 26-20 NFC wild-card overtime victory over the Saints.

He tore his ACL during his fourth game as a rookie in 2017, and played only 18 snaps over a six-game stretch the next year. The Vikings tried on several occasions to get him back in at least a limited capacity from a hamstring injury.