“The leaders discussed their shared concern about the Russian military build-up on Ukraine’s borders and Russia’s increasingly harsh rhetoric,” the White House said in a readout of the call among Biden, French President Emmanuel Macron, British Prime Minister Boris Johnson, Italian Prime Minister Mario Draghi and German Chancellor Angela Merkel.President Biden© Associated Press President Biden

“They called on Russia to de-escalate tensions and agreed that diplomacy, especially through the Normandy Format, is the only way forward to resolve the conflict in Donbas through the implementation of the Minsk Agreements,” the readout continued.

The call was meant to demonstrate solidarity between the U.S. and its European allies ahead of the one with Putin, which is expected to focus on the escalating Russian aggression near Ukraine.

Russia has amassed tens of thousands of troops on the border with its western neighbor, raising concerns in the U.S. and Europe about the possibility of a Russian military invasion. Current and former officials have compared Russia’s recent behavior to its activity in the lead up to the 2014 invasion of Ukraine’s Crimean Peninsula, which Moscow continues to occupy to this day despite international condemnation.

A senior administration official told reporters earlier Monday that Biden would speak with the European leaders “to coordinate his message and ensure that he goes into that conversation with President Putin with allied unity and strong transatlantic solidarity on the way forward.”

During the call, the leaders “underscored their support for Ukraine’s sovereignty and territorial integrity” and agreed to stay in touch “on a coordinated and comprehensive approach,” according to the White House readout.

The readout did not specify if the leaders discussed potential economic sanctions and other measures they could impose on Russia in the event of an invasion of Ukraine, though such measures have been a topic of conversation in recent days.

Biden administration officials have made clear that the U.S. and Europe are weighing economic sanctions on Russia as an option to respond should Putin decide to invade Ukraine.

“We believe that we have a path forward that would involve substantial economic countermeasures by both the Europeans and the United States that would impose significant and severe economic harm on the Russian economy should they choose to proceed,” the senior administration official said.

Biden is expected to hold a call with Ukrainian President Volodymyr Zelensky in the days after his call with Putin. Secretary of State Antony Blinken phoned Zelensky on Monday to discuss Russia’s behavior.