Volodymyr Zelenskyy has described Donald Trump’s decision to roll back sanctions on Russia as a “reward” for Vladimir Putin and warned it will embolden the Russian leader and intensify the Kremlin’s war, as Moscow launched one of its worst strikes yet on Ukraine’s power plants in an attempt to black out the country’s cities before winter.

The Ukrainian president also said he expected the Trump administration to lift more sanctions against Russia in the future and called for Europe to establish its own negotiations with Moscow as the US has sought better ties and business deals with the Kremlin.

“Unfortunately, the lifting of sanctions will continue, and I believe that the ‘diesel deal’ is the first step,” said Zelenskyy on Saturday. “Unfortunately, it seems to me that this cannot stop Putin; on the contrary, he feels joy and happiness that he has such support.”

In a social media message earlier, Zelenskyy wrote: “A US ⁠sanctions blackout, easing pressure on the aggressor, financial rewards for Putin – all of this only encourages him to keep attacking. We must not give up ground.

“We must keep trying to end the ‌war. To end it, not give Putin every reason to continue it indefinitely.”

In its latest effort to reduce tensions with Russia, Trump announced on Friday that he would put a hold on a sweeping new sanctions package targeting the Russian economy, telling Congress the pause on the legislation passed by both chambers was in the national interest.

The act, named for the late senator Lindsey Graham, who championed the legislation, would have introduced tough new sanctions on Russia including a 100% tariff on major importers of Russian oil such as China and India, as well as sanctions on Russia’s energy sector, financial institutions and shadow fleet of oil tankers.

On Saturday, Zelenskyy said the decision to waive the sanctions would encourage Vladimir Putin to intensify the war in Ukraine and called for support in the US to resurrect the bill.

“At the time when the Russians launched such a massive strike against our energy sector, in America, regrettably, a decision was made to completely ignore the Lindsey Graham law, which was supposed to impose truly effective pressure on Russia to end this war,” he wrote in a statement. “This law could have – and still can! – help a great deal. But the law needs to actually work, and every voice in support of it matters.”

The move was greeted by the Russian presidential envoy, Kirill Dmitriev, who wrote on social media: “The Trump administration’s suspension of the Graham Act is an important and truly historic moment.”

The legislation, which sanctions Russian officials, banks and a shadow fleet of tankers that keeps the country’s energy supplies moving, was due to be implemented in two days.

It also directs Trump to impose up to 100% tariffs on the top five importers of Russian oil or natural gas, with an exception for countries that import less than 15% of Russia’s natural gas exports and have taken significant steps to reduce those imports.

Friday’s announcement comes a week after Trump said the US had agreed to purchase diesel from Russia to try to bring down global energy prices, upending years of US and western pressure on the Kremlin to end its war against Ukraine.

Trump said last week that Russia would immediately supply more than 300,000 tonnes of diesel, followed by an additional 500,000 tonnes in November and 1m tonnes “immediately thereafter”. Russia would deliver an additional 3m tonnes “within a short period of time” after that, he wrote.

The Trump administration’s decision to waive the sanctions is the latest consequence of a brutal quarrel between Trump and Zelenskyy. Several times this week, the US did not provide intelligence of impending ballistic missile attacks to Ukraine, and the White House reportedly ordered the Pentagon to throttle the military-grade version of the Starlink satellite internet network used by Ukraine’s armed forces to run its drone operations on the frontline.

“We very much hope – and I personally hope – that the president of the United States of America will do everything so that Putin stops the killings, stops the strikes on our energy infrastructure, and stops this war,” Zelenskyy said on Saturday. “But once again, you cannot achieve this by restricting Ukraine’s responses to Russia for killing our people. And even less so by lifting sanctions.”

Trump has demanded that Ukraine halt its strikes on Russian oil refineries, as he has blamed the war in Ukraine, rather than the closure of the strait of Hormuz, for the worldwide spike in diesel prices. Ukraine unilaterally halted the strikes after Trump declared an “energy ceasefire” last week, but resumed them when it became clear that Russia was stepping up its attacks on Ukrainian power plants and substations.

Zelenskyy said on Saturday that Russia had launched one of its worst strikes yet against the country’s energy infrastructure, hitting more than 15 critical power generation and transmission facilities and causing “severe consequences”.

He also indicated that Ukraine’s dwindling stock of anti-air weapons made it difficult to shoot down many of the loitering munitions, cruise missiles and ballistic missiles being launched each night at Ukraine.

“Although our warriors are shooting down a significant number of them,” he said, the “sheer scale and unrelenting pace of Russia’s strikes, specifically against our energy sector, are unfortunately having severe consequences.”