KABUL—U.S. and Taliban negotiators have forged a preliminary deal on two vital points to end the war in Afghanistan, the special U.S. envoy said Monday, as the Afghan president urged the insurgents to negotiate directly with his government.

Washington agreed on the withdrawal of its approximately 14,000 troops from Afghanistan while the insurgents vowed to halt any terrorist attacks abroad from Afghan soil, said a person briefed by a Taliban participant in the talks last week in Qatar.

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