An official Syrian newspaper on Saturday launched a stinging attack on UN humanitarian chief Valerie Amos, and demanded that she be replaced.
"In her reporting, she has brought together an entire anthology of false and hypocritical terms that we find in Western rhetoric," said Al-Thawra.
"She wrote her report with the approval of Western capitals," the paper added.
Last week, Amos warned that instead of alleviating the misery for millions of Syrians in urgent need, a UN Security Council resolution designed to provide them with aid was failing.
"Far from getting better the situation is getting worse. Violence has intensified over the last month, taking an horrific toll on ordinary civilians," Amos told reporters.
The UN had asked Syrian authorities for permission to pass through a number of border crossings to reach an extra 1.4 million people immediately, but there had been no progress, Amos said. She demanded a "step change in delivery".
Al-Thawra attacked Amos for her claims.
"Whatever the Americans do not say, Amos says. What the French do not dare to say, she expresses. Whatever embarrasses the British, she adopts. Whatever the Israelis consider secondary, she emphasises. She has become a tool of the campaign" against Syria, Al-Thawra said.
Syria's regime has insisted ever since the start of a revolt in March 2011, that later morphed into a war, that all violence afflicting the country is the result of a foreign-backed "terrorist" plot.
"Amos is no longer worthy of her mission, and the UN must urgently extinguish the fire lit up by her lies. She undermines the UN's work and credibility," said Al-Thawra.
Amos had demanded "a step change" in how the Security Council resolution must be implemented.
Rights groups have slammed the Syrian government for failing to comply with the UN resolution, by refusing to allow aid to cross opposition-held border crossings.