US President Donald Trump has said his decision to suspend several Russian sanctions is an effort to keep Moscow at the negotiating table.
"I am in the process of negotiating Peace in the war between Russia and Ukraine," Trump said on his Truth Social messaging platform, adding that he didn't want to "do anything that will drive, foolishly, Russia away from the bargaining table".
Trump blocked numerous sanctions on Russia on Friday night, two days before they were due to take effect, as a row with Ukrainian President Volodymyr Zelensky deepened.
Zelensky told NBC News on Sunday that siding with Russian President Vladimir Putin would be a "historic mistake".
Russian envoy Kirill Dmitriev has responded to Trump's order by calling it "an important and truly historic moment". He said the sanctions, which were passed by the US Congress and signed into law by the US president in September, would have inflicted "serious damage" on the US and global market.
US Secretary of State Marco Rubio has described the suspension of the sanctions as a 60-day pause during which their potential impact on the US and global economies would be analysed.
In his Truth Social post, Trump also said Zelensky "doesn't want to end this war, and probably never did", adding "he could have made a better deal two years ago than he can now".
Zelensky has pushed for an end to fighting, and has repeatedly said that Putin doesn't want peace, since Russia launched its full-scale invasion of Ukraine in February 2022.
Relations between Washington and Kyiv frayed after the US struck a controversial deal to import Russian diesel last week.
Despite the international sanctions, Russia has still been able to export oil, much of it to China and India - often at attractive discounts. According to the think-tank Centre for Research on Energy and Clean Air (CREA), China has taken about half of Russia's crude exports, with India accounting for about 37%.
In remarks to a European Union summit, after Trump announced the deal to buy diesel from Russia and said Zelensky was "more difficult to deal with" than Putin, Zelensky said it was nice to be among "real leaders".
Zelensky has repeatedly pushed for stringent sanctions to limit funding that Russia can use in its war effort. After the latest move from the US, however, he said he believed the Trump administration would lift more sanctions against Russia.
Ukraine and its European allies criticised Trump's plans to import Russian diesel to help lower US energy prices, which have skyrocketed during the Iran war.
The deal, according to Zelensky, was tantamount to the US investing in Russia's war effort.
Concerns that Trump is siding with Russia have been heightened by disruption to Starlink, a US-provided satellite system used by Ukraine. That hampered Kyiv's ability to protect itself from Russian attacks.
Zelensky said US officials had linked speed restrictions to technical issues.
However, he said Ukraine had tested Starlink on EU territory and found it was operating at higher speeds.
Trump has denied both deliberately slowing down the network and a further accusation from Zelensky that the US had stopped sharing defence intelligence.