Cole Hocker admits he is "extremely disappointed" after the Olympic champion was disqualified in the 1500m at the World Athletics Championships.

The Team USA star was judged to have illegally pushed past Germany's Robert Farken during the semi-finals on Monday, falling foul over "jostling" rules (TR17.1.2[J]).

And Hocker intends to now focus on the 5000m, with the Friday's semi-finals affording him a chance at redemption.

"Extremely disappointed not to get the chance to defned my 1500m title this year," Hocker said.

"As always, championships are unpredictable, but there's no time to feel sorry for myself. Looking forward to the first round of the 5k this Friday."

Hocker's agents, Flynn Sports, have taken a swipe at what they have described as "amateur officials," with the United States Track & Field team's appeal failing.

"We want to be a professional sport but are directed by amateur officials who can't see the value of the world seeing the best 1500m race in the world," Flynn Sports wrote under an Instagram post from Hocker's training group Team Sova.

The initial post was also critical of the ruling, claiming Hocker was only guilty of "wanting it more," before pointing out the 24-year-old is still racing in Tokyo and set to compete in the men's 5000m, which starts with the semi-finals on Friday.

Farken was advanced to the final, with South Africa's Tshepo Tshite pushed into the top-six to take the final spot.

"We are disappointed by the decision to disqualify Olympic champion Cole Hocker from the men's 1500m final," said the United States Track & Field team. "We believed we had grounds for an appeal and unfortunately, that appeal was denied."

Hocker was running in the second of two heats in the 1500m semi-finals. It was a physical race from the start, with Canada's Foster Malleck and Italy's Federico Riva falling on the track close to the midway point after getting caught in a pack and tripping.

Hocker found himself in traffic as he entered the final straight. The 24-year-old rounded the final bend behind Farken and with the Netherlands' Stefan Nillessen on his left. Hocker made his move and looked to squeeze through Farken and Nillessen, but in doing so pushed into the German with his right arm and then held his arm across Farken's body.

As Hocker came through the gap, Farken and Nillessen dropped away, finishing 9th and 10th in the heat respectively. Great Britain's Neil Gourley came through behind Hocker to also take a spot and join defending world champion Kerr and Jake Wightman in the final.

Former 1500m world champion Steve Cram, who was commentating for the BBC, said Hocker had "panicked" and agreed with the decision to disqualify the reigning Olympic champion.

"You can't do this, really," Cram said. "I know the gap was there, if he'd been a bit more patient. He uses his elbow, puts it across Farken, who may or may not have got in, it was down to thousandths of a second as it was with Neil Gourley.

"The Americans will counter-protest. They are absolutely miffed. That's the Olympic champion, that's not good for the sport and we'd love him to be there. But at the same time Hocker panicked there and he did impede the German athlete."

Before learning of his disqualification, Hocker defended his move and told Citius Mag: "Obviously I'm not trying to affect anyone else's race. I was just trying to get to the line in that top six position. Obviously, like, everyone else was. I would have liked to have it a little bit cleaner, but, yeah, it was what it was."

With Norwegian star Ingebrigtsen crashing out of the 1500m in the first round, two of Kerr's main rivals will now miss out on the final. The 20-year-old rising star Niels Laros qualified with the fastest time of the semi-finals. Kerr's heat also saw jostling, with the Scot tumbling to the track after crossing the finish line.

Cole Hocker breaks silence after being disqualified in 1500m