Vladimir Putin is preparing for a long war in Ukraine, with even victory in the east potentially not ending the conflict, US intelligence has warned.
The warning comes as fierce fighting continues in the east, where Russia is trying to take territory.
But despite this, its forces remain in a stalemate, US intelligence said.
Avril Haines, the director of national intelligence, told a US Senate committee hearing on Tuesday that Mr Putin was still intending “to achieve goals beyond the Donbas”, but that he “faces a mismatch between his ambitions and Russia’s current conventional military capabilities”.
She added that the Russian president was “probably” counting on US and EU support for Ukraine to weaken as inflation, food shortages and energy prices got worse.
However, the Russian president could turn to “more drastic means” as the war continues – although Moscow would only use nuclear weapons if Mr Putin perceives an “existential threat” to Russia.
Defence Intelligence Agency Director Scott Berrier told the same hearing that the Russians and the Ukrainians were “at a bit of a stalemate”.
Between eight and 10 Russian generals have been killed so far, he added.
In Ukraine, bodies of 44 civilians have been found in the rubble of a collapsed building in the city of Izyum as the battle for control of the area rages.
The five-storey building collapsed in March as residents hid in the basement from Russian shelling, but rescuers have only just been able to reach the building.
The final battle for Mariupol is being fought in the sprawling Azovstal steelworks, where hundreds of Ukrainian fighters are holed up in underground tunnels and bunkers, surrounded by Russian troops.
Capturing Mariupol is a key war aim of Moscow, because doing so would give it control of one of Ukraine’s biggest ports and easier access to the wider region.
In the eastern city Odesa, missiles struck several buildings overnight and shook homes nearby. One person was killed and five people were injured, Ukraine’s armed forces said.
