Arkady Rotenberg, a childhood friend and former judo sparring partner of Russian President Vladimir Putin, is development manager and an executive committee member of the International Judo Federation.
The Russian billionaire was one of 20 people from Putin's inner circle hit by economic sanctions imposed last week by President Barack Obama following Russia's annexation of the Crimean Peninsula from Ukraine.
Rotenberg is also on the executive committee of the SportAccord Convention, an annual conference of Olympic and sports industry leaders. The 2014 convention will be held next month in Antalya, Turkey.
IJF President Marius Vizer said the U.S. action against Rotenberg "seems very bizarre to me," insisting it was up to Russia and Ukraine to solve their problems through "direct dialogue."
"I do not see any connection with the application of sanctions by the United States against a private person who does not have anything to do with the process and the political decisions that occurred between the two states," Vizer said in a statement to The Associated Press.
He said Rotenberg "honours us and remains rooted in our community" and will continue to carry out his judo roles.
"His freedom of movement might be affected by these arbitrary measures and his activity might be more difficult in these conditions, but all the other IJF officials will compensate these flaws, thus showing their solidarity towards Mr. Rotenberg," Vizer said.
Vizer, a Romanian-born Hungarian, also heads SportAccord, an umbrella body representing Olympic and non-Olympic sports federations. He is also president of the SportAccord Convention, which next meets in Antalya from April 6-11.
Rotenberg is expected to attend the conference in Turkey.
In a statement Monday, the convention said "according to our knowledge, there is no international framework" to apply U.S. sanctions against Rotenberg.
"The SportAccord Convention team fully supports Mr. Rotenberg and we all hope that this unpleasant situation will be soon settled," the statement said.
Arkady and his brother Boris Rotenberg, who was also hit by the U.S. sanctions, are reported to be worth $2.2 billion and $1.4 billion, respectively. They have held big state contracts, and Arkady Rotenberg's companies won billions in road contracts in Sochi, the host of the 2014 Winter Games.
The Russian Forbes magazine estimated that Rotenberg received more than $28 billion in state contracts in the past five years.