Ukraine's army leader admitted Sunday that Kyiv's position on the battlefield has worsened after Russian forces captured another village in the east, pressing their advantage in manpower and ammunition.
Russia's troops are advancing in the eastern Donetsk region as Kyiv awaits the arrival of much-needed US weapons that it hopes will stabilise the fragile front lines.
"The situation at the front has worsened," Ukrainian commander-in-chief Oleksandr Syrsky said in a Facebook post Sunday.
Ukrainian troops had "retreated" westwards to new defensive lines in a section of the front that runs past the city of Donetsk, controlled by pro-Russian forces since 2014.
Russia has "a significant advantage in forces and means" and had been able to notch up advances amid "heavy fighting", Syrsky said.
"In some sectors the enemy had tactical success, and in some areas our troops managed to improve the tactical position," he added.
Russia's defence ministry earlier on Sunday claimed its troops had captured the village of Novobakhmutivka in the Donetsk region -- around 10 kilometres (six miles) north of Avdiivka, which they seized in February.
The stark assessment of the picture facing Ukrainian troops comes at the end of week of ups and downs for Kyiv.
The United States finally approved a $61 billion package of financial aid after months of political wrangling, unlocking much-needed arms for Ukraine's stretched troops.
But on the battlefield Russia chalked up more successes.
Its troops managed to make rapid advances in a narrow column to the northwest of Avdiivka.
In the village of Vozdvyzhenka, some eight kilometres from the fighting in Ocheretyne, AFP reporters saw civilians loading a small truck with furniture and belongings on Sunday.
"We're going a long way from here... I don't have time to talk because of the shelling," one of them told AFP, before climbing into the vehicle and speeding out of the village.
Soldiers on the side of a road in the woods said they had originally been sent to build defensive lines.
"But the situation has changed. We were told not to take the shovels but to stay and wait for orders. The Russians are attacking and advancing," one told AFP, speaking on condition of anonymity.
Syrsky confirmed on Sunday that Russia had made some "tactical" progress in that part of the front, but said Moscow had not yet achieved what he called an "operational advantage".
He also said additional units were being deployed to replace those that had sustained heavy losses.
The recent setbacks have prompted rare criticism from Ukraine's military bloggers.
"The (Russian) breakthrough near Ocheretyne revealed a number of problems," the Deep State Telegram channel, with close links to the Ukrainian army, said in a post on Wednesday.
It said leaders of the 115th mechanised brigade, which is fighting in the area, were "responsible for the collapse of the defence in the entire sector, allowing significant losses".
Kyiv's forces are outnumbered across the battlefield, with the country struggling to recruit enough soldiers to replace those who have been killed, wounded or exhausted by the war, now in its third year.
Leaders in Kyiv have warned the military outlook could worsen in the next few weeks, while shipments of US weapons are making their way to the front lines.
Speaking after talks with Hakeem Jeffries, leader of the Democrats in the US House of Representatives, he said he had once again stressed the urgent need for Patriot anti-missile systems "as soon as possible".
Ukraine's head of intelligence at the ministry of defence Kyrylo Budanov said this month that the battlefield situation would likely be at its most difficult in mid-May to early June.
