A senior Russian official says the government has not ruled out buying a stake in aluminum giant Rusal from tycoon Oleg Deripaska in order to protect the company from U.S. sanctions.

Industry and Trade Minister Denis Manturov spoke briefly about the issue on April 24, a day after the United States said it could lift the sanctions against Rusal if Deripaska ceded control.

"I think that this option is not ruled out, but there have been no detailed discussions on this matter yet," Manturov said of the possibility that the state could buy a stake in the company from Deripaska.

Deripaska and Rusal were among 24 prominent Russians and 14 entities hit with U.S. sanctions announced on April 6 in response to "malign activity" by Moscow, including its alleged meddling in the 2016 U.S. election.

But the U.S. Treasury Department said on April 23 that it was giving customers of Russia's biggest aluminum producer more time to comply with the sanctions, and that it could lift them if Derispaska gave up his controlling stake.

"Rusal has felt the impact of U.S. sanctions because of its entanglement with Oleg Deripaska, but the U.S. government is not targeting the hardworking people who depend on Rusal and its subsidiaries," Treasury Secretary Steven Mnuchin said.

"Rusal has approached us to petition for delisting," Mnuchin said. "Given the impact on our partners and allies, we are issuing a general license extending the maintenance and wind-down period while we consider Rusal's petition."

The Treasury Department said that "the path for the United States to provide sanctions relief is through divestment and relinquishment of control of RUSAL by Oleg Deripaska," the well-connected billionaire who owns a 48 percent stake in Rusal.

The moves sent Rusal's soaring by over 15 percent, while aluminum prices fell sharply.

Rusal, the world's second-largest aluminum maker, was among the companies hit hardest by the sanctions announced on April 6, which caused a steep selloff in Russian stocks and the ruble.

The value of Rusal's stock had been cut in half by the beginning of this week, with investors fearing it could go out of business as customers around the world sever ties because of the sanctions and as its financing dries up in U.S.-dominated financial markets.

Russian President Vladimir Putin's spokesman declined to comment in detail on the U.S. Treasury department's latest statements about Rusal.

"In this case I would be rather cautious, as these statements are so hypothetical," Kremlin spokesman Dmitry Peskov said on April 24.

"It is clear that the decisions that have been taken are a painful blow to aluminium buyers on many continents, and naturally buyers are asking themselves why they have to bear the burden," Peskov said.

Deripaska has denounced the sanctions as "ridiculous" and Russia has described them as a thinly veiled attack on its economy.

In its April 23 announcement, the Treasury effectively gave Rusal months longer to sell off large quantities of aluminum that have been piling up at its factories unsold since the sanctions were imposed.

The stockpiles of aluminum will now be easier to sell because the Treasury said it will give U.S. customers of Rusal until October 23 instead of June 5 to wind down their business with Rusal.

The Treasury also said it will not impose secondary sanctions on companies outside the United States that do business with Rusal and its subsidiaries. The decision not to impose secondary sanctions particularly benefits European customers of Rusal.

French President Emmanuel Macron, who is visiting Washington this week, and other European leaders have worked behind the scenes to persuade U.S. President Donald Trump to ease the new sanctions on Russian business tycoons to ensure that European businesses are not unfairly penalized. Mnuchin said in his announcement that he factored the "impact on our partners and allies" into his reprieve.

Rusal's aluminum customers also now have more time to seek other suppliers.

Last week, aluminum prices hit their highest levels since mid-2011 amid fears the global market could face shortages as a result of the U.S. sanctions.

Wood Mackenzie, a Britain-based consulting firm, said that the Treasury' Department's announcement provided "much-needed breathing space" for the aluminum market.

Rusal and Deripaska did not immediately respond to the Treasury Department announcement.

Besides being close to the Kremlin, Deripaska is a former associate of Paul Manafort, who was Trump's campaign chairman ahead of he 2016 election and is a top target of U.S. Special Counsel Robert Mueller, who is investigating Moscow's alleged meddling as well as ties between Trump associates and Russia.

With reporting by AFP, AP, TASS, and Reuters