The UN envoy to Afghanistan has said that Afghan security forces are "undeniably stretched" but resilient amid a push by insurgents for more territory.
"The Afghan National Security Forces face operational challenges, their commitment is beyond question and they are demonstrating resilience in the face of insurgent efforts to take and hold ground," UN envoy Nicholas Haysom told the UN Security Council.
Taliban fighters, who ruled Afghanistan with an iron fist from 1996 to 2001, are pushing to take back territory more than 13 years after they were ousted in a US-led war.
"There also remains considerable concern that Islamic State [Isis] is seeking to establish a foothold. This demands greater regional involvement and collaboration to address this shared threat," Haysom continued.
IS has declared a caliphate in the territory it controls in Syria and Iraq. A US-led alliance has been targeting the radical Islamist group with air strikes in the past year.
The Taliban wrote to an IS leader urging the rival jihadist group to stop recruiting in Afghanistan, saying there is room for only "one flag, one leadership" in their fight to re-establish strict Islamist rule.
Haysom said no progress would be made toward peace in the region unless the government and the Taliban met directly to try and broker an end to the conflict.
"While the government has repeatedly stated its readiness to engage in direct talks with the Taliban, what is still missing is a clear indication from the Taliban that they are ready to engage directly with the government," he said.
"Direct engagement is necessary for a negotiated agreement," Haysom said.