MOSCOW — Six-time Olympic gold medalist Viktor Ahn wants to know why he has been barred from next month’s Pyeongchang Games.

Ahn is a short-track speed skater who was born in South Korea but switched allegiance to Russia ahead of the 2014 Sochi Games. Russian officials say the International Olympic Committee has refused to grant Ahn an invitation amid its vetting of the country’s athletes for possible doping links.

“It is outrageous that there is no concrete reason which explains my exclusion from the Olympics, and furthermore people now view me as an athlete who used doping,” Ahn wrote in an open letter to IOC President Thomas Bach.

Competing in South Korea would have been “an especially significant part of my career for several reasons,” said Ahn, who won his first three Olympic titles while competing for his native country. “I hope that the IOC will ultimately declare their reason for my exclusion, so I will be able to defend my honor and dignity.”

Ahn’s letter was published on Friday by the Russian Skating Union, hours before the IOC published its rules of conduct for Russian athletes and officials who will be at Pyeongchang.

All Russian athletes must sign an IOC-drafted integrity declaration confirming they are not currently under investigation for a doping violation, and agree to be removed from the team if their statement proves incorrect.

The spokesman for President Vladimir Putin, when asked about Ahn’s letter, said Russia would support all athletes, whether they take part in the Olympics or are barred.

“Intensive contacts are under way with the International Olympic Committee to clarify the situation and so that the interests of our athletes who are able to take part in the Olympics are completely secured and respected,” spokesman Dmitry Peskov said.

“There are athletes who are disputing their rights in a legal context. There are athletes who are appealing to public opinion. There are athletes who are appealing to the Olympic committee leadership. That is their right.”

The IOC hasn’t confirmed which Russians will be invited to compete in Pyeongchang, and hasn’t explained any individual decisions. However, it has said newly obtained records from the Moscow anti-doping laboratory played a role in the decision-making.

Russia announced 169 athletes would represent the “Olympic Athlete from Russia” (OAR) team on Thursday. The list didn’t contain Ahn or some other Russian medal contenders, including cross-country skiing world champion Sergei Ustyugov and biathlete Anton Shipulin.

The IOC refusals for some are separate from the doping bans for 43 Russian athletes because of what the Olympic body ruled was a doping program and cover-up at the Sochi Games. Of those, 42 have launched appeals at the Court of Arbitration for Sport, and verdicts in 39 cases heard in Geneva are due to be published next week.

Strict rules imposed on Russian medal winners in Pyeongchang were published in the IOC conduct guidelines Friday.

The official Russian flag can be hung in an athlete’s bedroom in Olympic villages, though with “no public visibility.”

Inside Olympic venues, athletes must not accept the Russian flag from a spectator nor sing the national anthem.

“Any ‘alternate’ victory ceremonies organized for OAR athletes and/or team officials are not permitted.”

Also, the International Biathlon Union said it could cancel a World Cup in Russia in March in light of “newly available information.”

The IBU didn’t say what it received, though the IOC said on Wednesday it was sharing doping-related information from its vetting process with international sports federations.

The World Cup in Tyumen is due to be the first in Russia since 2015.

AP Sports Writer Graham Dunbar in Geneva contributed to this report.