The United States said on Monday it was "outraged" by reports that a humanitarian aid convoy was bombed near Aleppo, Syria.
"The destination of this convoy was known to the Syrian regime and the Russian federation and yet these aid workers were killed in their attempt to provide relief to the Syrian people," State Department spokesman John Kirby said in a statement.
"The United States will raise this issue directly with Russia. Given the egregious violation of the Cessation of Hostilities we will reassess the future prospects for cooperation with Russia," he added.