WASHINGTON — The White House on Tuesday accused the Russian government of engaging in a cover-up of the chemical weapons attack last week by Syrian forces that prompted U.S. airstrikes, saying that U.S. intelligence and numerous contemporaneous reports confirmed that the Syrians used sarin gas on their own people.

In a declassified four-page report that details U.S. intelligence on the chemical weapons attack, the White House asserted that the Syrian and Russian governments have sought to confuse the world community about the assault through disinformation and “false narratives.”

Senior White House officials, speaking on the condition of anonymity to discuss the government’s view, said Russia’s goal was to cover up Syrian regime culpability.