The ongoing exchange of daily aerial attacks, while positions on the battlefield's front line barely change, provided a backdrop to the visit by Ukrainian President Volodymyr Zelenskiy to the United States.
Zelenskiy is due to meet other world leaders, including US President Donald Trump, at the UN General Assembly in New York.
The Ukrainian leader is hoping to recruit their help to end Russia's more than four-and-a-half-year-old full-scale invasion of his country.
Russian President Vladimir Putin is not due to attend the annual event.
The war has had global repercussions.
The repeated attacks on Russian refineries, following Moscow's strikes on Ukraine's power grid, have caused international shortages of diesel and price spikes, according to Trump.
However, the global crunch also came after the Iran war led to curtailed oil shipments through the Strait of Hormuz.
Zelenskiy also wants help to ensure the flow of Ukrainian grain and other farm products to world markets through the Black Sea.
Russian attacks on cargo vessels have severely disrupted Kyiv's exports, hurting its economy and threatening global supplies.
French President Emmanuel Macron said on Tuesday that his country would provide Ukraine with more radars to help protect its power grid.
He said he discussed with Trump the possibility of a truce between Moscow and Kyiv on strikes on energy infrastructure and a "moratorium" on Black Sea attacks.
Zelenskiy began his New York visit by meeting US senators, thanking them for what he called strong bipartisan support for Ukraine and for recently passing a tougher Russian sanctions bill that Trump has signed into law.
Peace and security will be closer once the bill is fully implemented, he said.
Zelenskiy said on social media that he briefed senators on his proposals for de-escalation measures that he intends to discuss with Trump later Tuesday.
The Ukrainian leader also plans to again press Trump to send more US-made Patriot air defence systems that Kyiv desperately needs to stop Russia's ballistic missiles.
Ukraine said it struck the Kuibyshev oil refinery in Samara, southeast of Moscow, in an overnight attack.
Several drones hit their targets, sparking a large fire at the facility, according to a statement from Ukrainian special forces.
The refinery, owned by Rosneft, is a key fuel supplier for central Russia, producing petrol, diesel, fuel oil and other petroleum products, the statement said.
Ukraine said it struck the same refinery in June.
One person was killed and four others were wounded in the Samara attack, regional governor Vyacheslav Fedorishchev said.
He said "the enemy targeted industrial facilities", but did not specify which ones.
The Russian defence ministry on Tuesday said its forces downed 297 Ukrainian drones over 14 Russian regions overnight, as well as the illegally annexed Crimean Peninsula.
Russia's overnight attack on Ukraine included anti-ship missiles, ballistic missiles, cruise missiles and more than 200 drones, Ukraine's air force said.
The strikes killed four people in the central Ukrainian city of Dnipro, said Oleksandr Hanzha, head of the Dnipropetrovsk regional military administration.
The strikes across Ukrainian regions damaged homes, businesses and storage facilities, wounding at least five people, authorities said.
Five people were wounded in the capital, Kyiv, according to officials.
The Russian defence ministry said its forces struck metallurgical and chemical industries, the fuel and energy sector, and the military-industrial complex, as well as port infrastructure facilities in four regions of Ukraine.
