Sky news:
US intelligence agencies believe that a drone attack on the Kremlin this month was likely orchestrated by Ukrainian spies or military intelligence, according to the New York Times.
The newspaper said the attack appeared to be part of a series of covert operations that have made officials in the US - Ukraine’s biggest supplier of military equipment - uncomfortable.
Dramatic footage from the explosion earlier this month showed plumes of smoke rising over the Kremlin.
The US assessment was based on intercepted Russian and Ukrainian communications, the newspaper said.
US officials said they did not believe Ukraine's president Volodymyr Zelenskyy signed off on all covert operations, it added.
It is unclear to what extent he was aware of such operations in advance, the officials were quoted as saying.
The paper said the US intercepted Ukrainian conversations in which officials said they believed their country was responsible for the attack, and also tapped into Russian communications which indicated it was not some sort of false-flag operation by Russia.
In response to the report, Kremlin spokesman Dmitry Peskov said: "We immediately said that the Kyiv regime was behind this".
Mr Zelenskyy has denied any Ukrainian involvement.