He went on to say that the strategically important port city is now “contested territory.”

The claim contradicts a statement made on Friday by Major General Sergei Rudskoi, chief of the Russian military’s General Staff’s Main Operational Directorate, who stated that the Kherson region was fully under control.

Ukrainian officials questioned the Pentagon’s assessment, claiming that the city appeared to be firmly under Moscow’s control, despite the fact that Kyiv’s forces are fighting across the region.

Nexta, an East European news outlet, echoed the claim, tweeting: “Russian forces no longer have complete control of Kherson.”

According to US defence officials, any Ukrainian success in retaking Kherson would be a huge blow to Mr. Putin’s war effort and would make it more difficult for Russia to carry out any plans to seize control of Ukraine’s Black Sea coast and the port of Odessa.

According to a Pentagon official, losing Kherson would jeopardise Russian troops fighting in nearby Mykolayiv.

He went on to say that Moscow had begun mobilising Russian forces in Georgia to move to Ukraine.

According to The New York Times, the official also stated that Russian soldiers have taken defensive positions near Kyiv and abandoned efforts to capture it from the ground.

“They don’t show any sign of being able to move on Kyiv from the ground,” he added.

According to the official, US officials believed Russia was prioritising its fight in eastern Ukraine, where Russian-backed separatists have been fighting Ukrainian troops since 2014.

The senior defence official also stated that the US believes Russia is prioritising eastern Ukraine’s Donbass over Kyiv in an effort to gain leverage in negotiations and cut Ukrainian forces in the east off from the rest of the country.

Earlier on Friday, the Kremlin stated that the first phase of its “military operation” was nearly complete and that it would now focus on completely “liberating” Ukraine’s breakaway eastern Donbass region.

This appeared to indicate that Moscow was shifting to more limited objectives after encountering fierce Ukrainian resistance in a month of fighting.

According to a senior US official, Russia’s actions on the ground appear to broadly support Moscow’s announcement.

The official, who spoke on the condition of anonymity, told reporters, “They are prioritising it, and we concur, our information would concur, with that.”

Mr Rudskoi stated on Friday that 1,351 Russian soldiers were killed and 3,825 were injured during the “operation.”

According to Ukraine’s military, 15,000 Russian soldiers have been killed in action.

According to a US defence official, Russia’s combat power in Ukraine was between 85 and less than 90 percent of its pre-invasion levels.

After Russian troops invaded Ukraine on February 24, Kherson was the first major urban centre to fall into Russian hands.

Officials warned on Tuesday that 300,000 civilians in the occupied southern Ukrainian city were running out of food, highlighting what one international aid official described as a breakdown in Ukraine’s humanitarian system.

This week, Deputy Prime Minister Iryna Vereshchuk stated that Russian forces were preventing humanitarian aid from reaching civilians in Kherson.

Russia has encountered popular opposition in the city, with Ukraine’s armed forces reporting that Russian troops used stun grenades and gunfire to disperse a rally of pro-Ukrainian protesters on Monday.