As the war enters its 781st day, these are the main developments.

Fighting

• Ukraine’s army chief, Colonel-General Oleksandr Syrskii, said on Sunday that Russian forces aimed to capture the city of Chasiv Yar by May 9, setting the stage for an important battle for control of high ground in the east where Russia is focusing its assaults.
• The fall of Chasiv Yar, west of the shattered city of Bakhmut, by the date Moscow marks the Soviet victory in World War II would indicate growing Russian battlefield momentum as Kyiv faces a slowdown in Western military aid.
• Rob Lee, a senior fellow at the Foreign Policy Research Institute, a think tank in Philadelphia, said on X that Chasiv Yar would likely prove an important battle. “Chasiv Yar is located on defensible high ground. If Russia takes the [town], they could potentially increase the rate of advance deeper into Donetsk [region] as part of an expected summer offensive,” he said.
• Separately, fragments from a downed Russian missile fell on a settlement outside the central Ukrainian city of Dnipro on Sunday, injuring 12 people, the regional governor Serhiy Lysak said.
• Lysak also said Russian forces used artillery in 11 attacks on the town of Nikopol, a frequent target opposite the Russian-held Zaporizhzhia Nuclear Power Plant. He said four people had been injured.
• Ukrainian President Volodymyr Zelenskyy told Ukrainians in his nightly address on Sunday: “The situation at the front during such a hot war is always difficult. But these days – and especially on the Donetsk front – it’s getting harder.”

Politics and diplomacy

• President Zelenskyy on Sunday condemned Iran’s drone and missile attack on Israel and said his country needed help from its allies to fend off threats from the air, just as Israel did.
• Zelenskyy again called on the United States Congress to approve a vital aid package that has been blocked for months by political wrangling.

• US House of Representatives Speaker Mike Johnson said on Sunday he would try to pass aid to Israel this week but did not say whether the legislation would also include assistance for Ukraine and other US allies.

• According to an exclusive by the Reuters news agency, Russian Copper Company (RCC) and Chinese firms have avoided taxes and skirted the impact of Western sanctions by trading in new copper wire rods disguised as scrap.

Weapons

• Germany will deliver a US-made Patriot air defence system and air defence missiles to Ukraine at a “critical time”, Zelenskyy said.
• “I am grateful to the chancellor for the decision to supply another, additional Patriot system to Ukraine, as well as missiles for the existing air defence systems,” the president said after speaking by telephone with German Chancellor Olaf Scholz.
• Ukraine’s leader said last week that the country needed 25 US-made Patriot air defence systems to protect the country from Russian attacks.