U.S. President Donald Trump spoke with Russian President Vladimir Putin on Monday, as Russia and Saudi Arabia have ramped up oil production, causing prices of the commodity to drop. The two leaders also discussed the ongoing coronavirus pandemic.

"The heads of state expressed serious concern regarding the scope of the spread of the coronavirus in the world," the Kremlin said in a statement.

They "discussed closer cooperation between the two countries," although details are not clear on what this cooperation might mean.

The two leaders also "exchanged opinions on the current state of the global oil market."

Trump announced he was speaking with Putin on the “Fox & Friends” program earlier in the day. Trump said he was going to speak with Putin about the energy markets, claiming that Saudi Arabia and Russia "both went crazy" about oil.

Saudi Arabia and Russia are competing for market share in the oil market, after a dispute about cutting production due to less global demand amid the ongoing coronavirus outbreak. Riyadh wanted to cut production but Moscow refused, as Russia believes this would help the U.S. shale industry, a major competitor to the Russian energy market.

Trump has instructed the Department of Energy to purchase oil for the nation’s strategic reserve, a boost for the U.S. oil industry amid the price war. Yet, the department has suspended its plans to buy oil for now, as funding for the operation was not included in the $2 trillion stimulus package last week.

During his interview with Fox News on Monday, Trump made other comments about his administration’s stance on Russia. He claimed that he has “been tougher on Russia than any president of our country.”

But many critics have long expressed concern about Trump's cozy relationship with Putin. Trump was reluctant to impose new sanctions against Russia in July 2017 and has praised Moscow for expelling U.S. diplomats.