By Jonathan Landay and David Brunnstrom
WASHINGTON, May 28 (Reuters) - The United States on Thursday leveled unusually harsh criticism against Russia and called for it to refrain from its promised "systematic strikes" against Kyiv, but Moscow brushed off the appeal and reiterated a warning to foreign diplomats to leave the Ukrainian capital.
The statements came during a U.N. Security Council session requested by Ukraine in response to Russia's bombardment by hundreds of drones and missiles on Sunday
against Kyiv and nearby areas.
The barrage included a strike by a nuclear-capable Oreshnik intermediate-range ballistic missile, at least the third time Moscow has fired the weapon into Ukraine since November 2024.
Condemning Sunday's barrage, Tammy Bruce, the deputy U.S. ambassador to the U.N., called Russia's use of the Oreshnik "an inexplicable, dangerous and barbaric escalation" of the war that erupted with Russia's full-scale invasion in February 2022.
"We caution Russia not to mount so-called systematic strikes against Kyiv, which risk further civilian casualties and setting back the prospect of peace," said Bruce.
At least two civilians died and around 100 were injured in the bombardment that Moscow said was in response to a Ukrainian strike on a student dorm in Donetsk, the eastern region of the same name that Moscow-backed separatists seized in 2014.
Bruce's comments were among the sharpest criticism of Russia to come from the Trump administration, which has generally taken a more accommodating stance toward Russia than most U.S. allies.
She did not say how the U.S. would respond if Moscow carried out its threat of "systemic strikes."
Russian Ambassador Vassily Nebenzia reiterated Moscow's assertion that Sunday's barrage targeted key Ukrainian military and intelligence facilities and renewed Russia's vow to launch new strikes on "decision-making centers and command posts."
"Since the above facilities are dispersed throughout Kyiv, we warned foreign citizens, including the staff of diplomatic missions and offices of international organizations, about the need to leave the city as soon as possible," he continued.
U.N. Assistant Secretary-General Khaled Khiari said the United Nations was "deeply concerned" by Russia's promised "consistent and systemic strikes" against targets in Kyiv.
(Reporting by Jonathan Landay and David Brunnstrom; Editing by Don Durfee and Stephen Coates)
