Avril Haines made the assessment in Congress on Thursday night, US broadcaster CBS News reported.
In a testimony before the Senate Armed Services Committee, she said the Russian army had gained less territory in April than in any of the prior three months, and was suffering from "significant shortfalls" in munitions as well as personnel constraints.
Haines, who is the director of national intelligence, stated: "If Russia does not initiate a mandatory mobilization and secure substantial third-party ammunition supplies beyond existing deliveries from Iran and others, it will be increasingly challenging for them to sustain even modest offensive operations," as quoted by US broadcaster CNN.
Russia to focus on consolidating already-occupied territory?
The US top spy said that Russian President Vladimir Putin "probably has scaled back his immediate ambitions" and would focus on consolidating control of already-occupied territory in the east and south of Ukraine.
Haines also said that Russian ground forces had been significantly degraded and, according to some estimates, could take between five to 10 years to rebuild, CBS News reported.
According to Haines, Russia's loss of conventional military power may make it more reliant on cyber, space and nuclear capabilities, as well as on support from China, amid a deepening relationship between Moscow and Beijing.
At the same time, the US intelligence chief said it was "very unlikely" Putin would resort to the use of nuclear weapons.
She added Putin’s strategy was likely to involve prolonging the conflict until Western support for Ukraine wanes, Britain’s The Guardian newspaper reported.
White House dismisses Russia’s claims US orchestrated Kremlin drone attack
Haines said the United States was “investigating” Wednesday's apparent drone attack on the Kremlin.
Russia said it had been an attempt to assassinate Putin, carried out by Ukraine and orchestrated by the United States, an accusation that both Washington and Kyiv immediately and firmly denied, according to news outlets.
"At this stage, we don't have information that would allow us to provide an independent assessment" of the Kremlin's claims, Haines told senators.
Meanwhile, the White House dismissed Russia’s accusations as “ludicrous,” saying the United States was not involved in the incident, Britain’s The Guardian reported.
National Security Council spokesman John Kirby told reporters on Thursday night: “One thing I can tell you for certain is that the US did not have any involvement with this incident, contrary to [Vladimir Putin's spokesman] Mr Peskov’s lies, and that’s just what they are: lies.”
Earlier, Dmitry Peskov said that “decisions about such terrorist attacks are taken in Washington” and that Ukraine “just implements these decisions.”
Friday is day 436 of Russia’s war on Ukraine.
(pm/gs)
Source: PAP, CBS News, CNN, The Guardian