WASHINGTON, April 21 (Xinhua) -- The U.S. Treasury Department said on Friday it will not issue drilling waiver to Exxon Mobil Corp. to work with a Russian state oil company as prohibited by U.S. sanctions on Russia.

"In consultation with President Donald J. Trump, the Treasury Department will not be issuing waivers to U.S. companies, including Exxon, authorizing drilling prohibited by current Russian sanctions," Treasury Secretary Steven Mnuchin said in a statement.

Exxon has reportedly been seeking the U.S. government's permission to work with Russia's state-run oil giant PAO Rosneft to drill for oil in the Black Sea, an area covered by U.S. sanctions imposed on Russia after the latter's annexation of Crimea in 2014.

In response, Exxon said that it understands Mnuchin's statement that was issued in consultation with President Trump.

"Our 2015 application for a license under the provisions outlined in the U.S. sanctions was made to enable our company to meet its contractual obligations under a joint venture agreement in Russia, where competitor companies are authorized to undertake such work under European sanctions," Exxon said in a statement.

The Exxon joint venture agreement with PAO Rosneft was inked in 2012 when incumbent Secretary of State Rex Tillerson was Exxon's CEO.

The State Department is one of several U.S. agencies tasked with approving sanctions waivers, but Tillerson has said that he will recuse himself from making decisions involving his former company for at least two years.