Ukrainian President Volodymyr Zelensky said on Tuesday that Russia was increasing its attacks across the front line, as Kyiv called for the West to boost weapons supplies ahead of winter.
Neither side has made any significant territorial gain for months, but both Zelensky and the Kremlin have denied the conflict has ground to a stalemate.
"The military reported an increase in the number of enemy assaults," Zelensky said in a post on social media, with Russians attacking around the cities of Donetsk, Kupiansk and Avdiivka.
Zelensky has warned Russia is likely to increase air strikes against Ukraine's energy infrastructure ahead of the winter, as it did this time last year.
He called strikes on the city of Kherson a day earlier that killed three people and wounded a dozen — including a newborn baby — "revenge" attacks that were "without any military necessity."
Andriy Yermak, Zelensky's chief of staff, met U.S. Secretary of State Antony Blinken in Washington on Monday as part of a trip to the United States to press Ukraine's need for Western weapons.
"As winter approaches, we expect the Russian missile terror to intensify," Yermak posted on Telegram after the meeting.
"Therefore, we are in dire need of air and missile defense systems that will protect Ukrainian cities, key critical infrastructure facilities, and grain corridor routes," he said.
Yermak later said he also met U.S. national security adviser Jake Sullivan as well as British and European security and foreign policy advisers to discuss the "situation on the battlefield."
Yermak said Russia has increased the number of its forces in Ukraine and that Kyiv "needs to maintain international support."
With the conflict dragging for almost 21 months, Ukraine fears growing Western fatigue and world attention on the Israel-Hamas war could weaken support for its army.
In a separate speech in Washington on Tuesday, Yermak said Ukraine had "gained a foothold on the left bank of the Dnipro," without providing further details.
The vast Dnipro River splits the frontline in the south of Ukraine, with Russian forces entrenched on the eastern, or left, bank and Ukraine on the opposite side.
Over the last few weeks, Russian military bloggers close to the armed forces have reported that Ukrainian forces had made successful amphibious landings on the Russian side.
They reported the Ukrainians established positions in the village of Krynky, around 35 kilometers (22 miles) upstream from Kherson.
Neither the Russian or Ukrainian defense ministries have commented on the reports.