Este sitio web fue traducido automáticamente. Para obtener más información, por favor haz clic aquí.

A senior U.S. defense official said Wednesday that the atrocities discovered in the Ukrainian suburb of Bucha outside of Kyiv over the last week were "premeditated" and "very deliberate."

"Just looking at the imagery, when you see individuals with their hands tied behind their backs and evidence of being shot in the head – that certainly appears to be premeditated. It appears to be planned. It certainly appears to be very, very deliberate," a senior defense official told reporters. 

WARNING: GRAPHIC IMAGE: Policemen work on the identification process following the killing of civilians in Bucha, before sending the bodies to the morgue, on the outskirts of Kyiv, Ukraine, on Wednesday.

WARNING: GRAPHIC IMAGE: Policemen work on the identification process following the killing of civilians in Bucha, before sending the bodies to the morgue, on the outskirts of Kyiv, Ukraine, on Wednesday. (AP/Rodrigo Abd)

RUSSIA-UKRAINE: LIVE UPDATES

"Clearly, the message was sent to the world of Russia's brutality, and that's a message that should not be forgotten here," the official added. 

Russia prompted global outcry this week after the bodies of hundreds of civilians were found on the streets and in mass graves in Bucha. 

More than 400 civilians are believed to have been killed by Russian troops in what the U.S., Ukraine and NATO have deemed evidence of war crimes.

Russia said last week that as part of the negotiating process it would withdraw troops from the capital city of Kyiv and the northern city of Chernihiv to "increase mutual trust." 

WARNING: GRAPHIC IMAGE A dog lays next to the body of a civilian in Bucha, Ukraine on Sunday. 

WARNING: GRAPHIC IMAGE A dog lays next to the body of a civilian in Bucha, Ukraine on Sunday.  (Reuters/Stringer TPX Images of the Day)

NATO EXPECTING 'MAJOR OFFENSIVE' FROM PUTIN EASTERN UKRAINE, ALLIANCE PREPARING FOR 'LONG HAUL' WAR

Officials have warned that this is a tactic to re-supply and re-arm its troops, and is not an attempt to deescalate the war. 

The senior U.S. defense official said that over the last 48-hours all Russian forces in and around Kyiv and Chernihiv have "completely withdrawn" and troops in northern Ukraine have moved into Belarus.

NATO Secretary-General Jens Stoltenberg told reporters Wednesday that the alliance is expecting a "major offensive" in eastern Ukraine as Russian President Vladimir Putin looks to secure the Donbas region after failing to take Kyiv. 

Stoltenberg said Putin will look to create a landbridge between the Donbas and Russia, and warned that there have been no indications that the Kremlin’s aim in Ukraine has changed. 

A Ukrainian serviceman stands amid destroyed Russian tanks in Bucha, on the outskirts of Kyiv, Ukraine, on Wednesday.

A Ukrainian serviceman stands amid destroyed Russian tanks in Bucha, on the outskirts of Kyiv, Ukraine, on Wednesday. (AP/Felipe Dana)

CLICK HERE TO GET THE FOX NEWS APP

"We have seen no indication that President Putin has changed his ambition to control the whole of Ukraine and also to rewrite the national order," he told reporters.

The senior defense official said it remains unclear exactly when Russia will re-deploy its troops back into Ukraine.