"It is imperative that we continue to reach all Syrians in need of humanitarian assistance," the UN chief said at the press encounter marking the 10th anniversary of the Syrian conflict at the UN headquarters in New York.
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The secretary-general warned that the situation "remains a living nightmare" in Syria.
"Hundreds of thousands of Syrians have died. Millions have been displaced. Countless others remain illegally detained and often tortured, missing, disappeared, or living in uncertainty and deprivation," he said.
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"For 10 years, the world has watched Syria spiral into destruction and bloodshed," said the top UN official.
Noting that some 60 percent of Syrians are at risk of hunger this year, Guterres noted that more humanitarian access is needed.
"Intensified cross-line and cross-border deliveries are essential to reach everyone in need everywhere," he said.
"This is why I have repeatedly urged the Security Council to achieve consensus on this crucial matter," he said.
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"The UN will continue its pursuit of a negotiated political settlement in line with Security Council resolution 2254," said the secretary-general. "The parties have the opportunity to demonstrate a willingness to find common ground and recognize the need for all Syrians, whom they represent, to move beyond a perpetual state of conflict."