US President Donald Trump has said that he would not schedule any talks with Vladimir Putin unless it was clear that the Russian President was serious about making a deal to end the war in Ukraine.
"I'm going to have to know that we're going to make a deal. I'm not going to be wasting my time," Mr Trump told reporters aboard Air Force One as he headed to Asia.
"I've always had a great relationship with Vladimir Putin, but this has been very disappointing," he said.
"I thought this would have gotten done before peace in the Middle East," Mr Trump added.
On Wednesday, the US sanctioned Russia's two largest oil companies and Mr Trump complained that his talks with Mr Putin over the conflict in Ukraine "don't go anywhere".
Mr Trump had held off pulling the trigger on sanctions against Russia for months, but his patience snapped after plans for a fresh summit with Mr Putin in Budapest collapsed.
The US President has however said he hopes that the sanctions on Rosneft and Lukoil are short-lived and that the "war will be settled".
Mr Putin admitted the sanctions were "serious" but insisted they were not enough to significantly damage the Russian economy.
He added that the sanctions were an "unfriendly act" that "does not strengthen Russia-US relations, which have only just begun to recover."
But the Russian leader said he remained open to dialogue with Mr Trump.
Ukrainian President Volodymyr Zelensky called the US sanctions "a strong and much-needed message that aggression will not go unanswered."
The European Union levied tough sanctions on the Russian oil and gas sector in parallel to the US measures.
