The Kremlin said on Wednesday that it thought it was too early for anyone to have an accurate picture of the extent of damage inflicted on Iran's nuclear facilities by U.S. bombing last weekend.

Asked if Russia had its own information on the degree of damage, Kremlin spokesman Dmitry Peskov said: "No. I don't think that anyone can have realistic data now. It's probably too early, we need to wait until such data appears."

U.S. President Donald Trump said at the weekend that the strikes had "obliterated" Iran's nuclear facilities.

However, three sources with knowledge of the matter told Reuters that a preliminary U.S. intelligence assessment had determined that the attacks had set back Tehran's program by only a matter of months.

Russia has condemned the strikes on Iran, with which it signed a strategic cooperation agreement in January, as illegal, unjustified and unprovoked.

Peskov said Russia had indications that there were open communications channels between Washington and Tehran, adding that Moscow was closely monitoring developments and still talking to Iran itself.