Russia's defense ministry said on Friday it had completed the withdrawal of troops from the western bank of the Dnipro river in Ukraine's southern Kherson region.

In its daily briefing, the ministry said all Russian forces and equipment had been transferred to the left, or eastern, bank of the Dnipro. It said the withdrawal was completed by 0500 Moscow time (0200 GMT) on Friday morning.

"The transfer of Russian troop units to the left bank of the Dnipro river has been completed," the defense ministry said in a statement.

"Not a single unit of military equipment or weapons have been left on the right (western) bank. All Russian servicemen crossed to the left bank," it added, saying that Russia had not suffered any loss of personnel or equipment during the withdrawal.

Reuters could not independently verify those details. Pro-Russian war bloggers had reported late on Thursday that Russian forces crossing the river were coming under heavy fire from Ukrainian forces. The ministry said Ukrainian forces had struck Dnipro River crossings five times overnight with U.S.-supplied HIMARS rocket systems.

Russia ordered the withdrawal on Wednesday, saying it had concluded that attempts to maintain its position and supply troops, including in the regional capital Kherson, were "futile" in the face of a mounting Ukrainian counteroffensive.

The speed of the withdrawal was faster than Ukraine and the United States had said they expected.

The top U.S. general said on Wednesday he estimated that Russia had 20,000 to 30,000 troops to move across the river, and the pullout could take "days and perhaps even weeks."

Ukraine's defense minister told Reuters in an interview on Thursday he expected the withdrawal to take at least a week.

The Russian defense ministry said it had adopted "defensive lines and positions" on the eastern bank of the river, which Moscow hopes it will be able to better supply and defend.

Initially skeptical over Russia's withdrawal plans, Kyiv has reclaimed dozens of towns and settlements that Russian troops have abandoned over the last 48 hours.

The withdrawal marks one of Russia's biggest retreats in its nine-month war, after failing in an initial advance on the capital Kyiv and being ousted from the northeastern Kharkiv region in early September.

But Kremlin spokesman Dmitry Peskov said on Friday Russia remained committed to achieving the goals of what Moscow calls its "special military operation," and said Moscow still viewed the Kherson region as "part of Russia."

President Vladimir Putin proclaimed Kherson - and three other regions of Ukraine - as part of Russia in a triumphal ceremony in the Kremlin on Sept. 30. Ukraine, its Western allies and an overwhelming majority of countries at the U.N. General Assembly have condemned the declared annexations as illegal.