There is “close to zero chance” Putin will agree to a ceasefire due to Trump's threats of tariffs and sanctions on Russia, said Eugene Rumer, a former U.S. intelligence analyst for Russia who directs the Carnegie Endowment for International Peace’s Russia and Eurasia Program.

"The key channel by which secondary tariffs on buyers of Russian energy could impact the global economy would be through the level of energy prices," says Kieran Tompkins from the consultancy Capital Economics. If the tariffs work, they will cut the flow of Russian oil and gas to global markets.