US President Donald Trump suggested that Ukraine “may be Russian someday,” throwing into question the future independence of a sovereign country that, with Western backing, has defended itself against Moscow’s full-scale invasion for nearly three years.

Ukrainians on Thursday worried that U.S. President Donald Trump was preparing to sell out their country following his phone call with Russian President Vladimir Putin, though some expressed cautious hope over his effort to swiftly end the war.

Oil prices could tumble if U.S. President Donald Trump is able to make good on his campaign promise to end the war in Ukraine. Trump said Wednesday that he and Russian President Vladimir Putin had agreed on a “lengthy and highly productive phone call” to open immediate talks to end the conflict,