Igor Sechin, the chief executive of Rosneft, Russia's top oil producer, has slammed the U.S.'s decision to hit him with sanctions, saying that the action does not "make any sense."
As a member of President Vladimir Putin's inner circle, Sechin was sanctioned following Russia's annexation of part of Ukraine. U.S. citizens are now barred from doing business with him and his U.S. assets have been blocked.
"I cannot understand any justification for taking these sanctions," Sechin told CNBC this week in his first-ever television interview.
"I cannot understand what purpose they are pursuing. I am not involved in political decisions… these decisions that target me do not make any sense to me."
Sechin was previously Putin's deputy chief of staff, and like the president, was once a Soviet intelligence officer.
He now heads Rosneft, the world's largest publicly traded petroleum company, which is 70 percent state-owned and produces 40 percent of Russian oil.
Rosneft itself has so far escaped international sanctions. It has continued to work with Western companies, including BP, which owns 20 percent of it.
Last month, the U.S.'s ExxonMobil extended a natural gas project with Rosneft and the Russian company signed a joint research agreement with General Electric.
"I don't think my active cooperation with American companies that is aimed at ensuring mutual profit, could be a basis for sanctions," Serchin said.
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Other Russian oligarchs hit by U.S. sanctions include Sergei Chemezov, the CEO of state-owned high-tech manufacturer Rostec. Chemezov also sits on the board of Rosneft, and like Serchin, has close ties to the Russian government.
The instigation of sanctions followed the ouster of Ukraine's then pro-Putin president, Vitor Yanukovych, and Russia's subsequent annexation of Ukraine's Crimea region.
Serchin, who has been referred to as "Putin's shadow", implied that sanctions were imposed by the West because politicians had panicked in response to Ukraine.
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"I think serious people should not take any serious decisions under pressure," he said.
"I think this sad situation was described quite well by the French politician, Charles Maurice de Talleyrand. So far as I remember, what he said was, 'Everything that is excessive does not have significance.'"
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Ukraine's new president, Petro Poroshenko, has called for fresh sanctions to be imposed on Russia, after separatist rebels shot down a military aircraft, killing 49 men at the weekend. A new round of penalties could potentially see Russian companies targeted as well as individuals.
Of this possibility, Sechin said: "We will continue working to demonstrate our efficiency in the joint work that would be beneficial to both Russian and American companies. However, if decisions are taken about sanctions, we will continue our projects ourselves, and leave the option open to our American partners to come back when it is possible".
—By CNBC's Katy Barnato