(Bloomberg) -- CIA Director Bill Burns warned Americans to be vigilant regarding Russian President Vladimir Putin’s designs on Ukraine as tensions soar between Moscow and Kyiv. 

“I would never underestimate President Putin’s risk appetite on Ukraine,” Burns said during an interview late Monday at the Wall Street Journal CEO Council Summit. “It’s so important to respond to that with a strong mix of deterrence as well as the possibility of diplomacy.”

Burns’ comments come as President Joe Biden prepares for a video call with Putin on Tuesday. Biden plans to use the call to warn Moscow against invading Ukraine or risk severe economic penalties, a senior Biden administration official told reporters Monday. Two people familiar with the matter said sanctions against Russia’s biggest banks are among the options. 

Putin’s deployment of troops and military equipment on Ukraine’s border has revived fears of war first raised in the spring, when he made similar moves. Those tensions subsided following an April conversation between the leaders, but that progress proved fleeting and U.S. officials say a fresh buildup of forces near Ukraine continues.

Biden Weighs Russian Banking Sanctions If Putin Invades Ukraine

Asked about China, Burns said that President Xi Jinping is likely interested in testing the possibility of establishing a “predictable relationship” with America, even if that relationship remains “highly competitive.” 

Burns also said that the Central Intelligence Agency is “not sure” whether Xi has a timeline for establishing mainland control over Taiwan, but that recent military exercises demonstrated his longer-term determination to do so. 

Burns added that the kind of “ubiquitous technical surveillance” seen in authoritarian states means that the CIA needs to “transform our operational tradecraft.” The agency would work to adapt its approach to meet these challenges in areas ranging from recruitment to communication, he added.  

©2021 Bloomberg L.P.