The U.N. chief stressed in a report to the Security Council circulated Thursday that "a sustainable peace agreement can be reached only through comprehensive intra-Afghan dialogue."
Guterres expressed hope that progress in U.S. talks with the Taliban will bring about direct talks between Taliban insurgents and the government.
"I call for the beginning of immediate, direct and substantive talks, towards the hope of ending this conflict and its unacceptable toll in lives," he said.
U.S. peace envoy Zalmay Khalilzad is currently holding talks with the Taliban in Qatar, which are now in their second week. This has raised expectations there could be some progress.
Khalilzad has said he sees himself as a "catalyst" to finding a formula for Afghans to sit down with each other and work out a roadmap for a peaceful future. He also said he wants intra-Afghan negotiations to start immediately.
Despite stepped-up U.S. efforts to end America's longest war, attacks have continued in Afghanistan.
Guterres said the security situation in the country remains volatile, with a high number of security incidents. Saying he remains "profoundly concerned by the impact of the armed conflict on the civilian population," he pointed to recent U.N. figures documenting "record-high numbers of civilian deaths" — 3,804 people killed in 2018.
Last year, the secretary-general said, the Taliban succeeded in temporarily capturing 21 district administrative centers, the second-highest level since Afghan forces took over responsibility for security at the end of 2014.
The Islamic State extremist group is also "resilient despite Afghan and international military forces maintaining a high tempo of operations against its strongholds in Nangarhar and Kunar provinces," Guterres said.
He added that the U.N. peacekeeping mission reported clashes in Kunar between IS and Taliban fighters.
On the political and diplomatic front, Guterres stressed that a cessation of violence isn't enough.
"To be durable, any peace process must be inclusive," he said. "There must be confidence in a shared future through the guarantee of the rights of all Afghans," including women who were harshly oppressed under Taliban rule.
He called on all parties "to facilitate the meaningful participation of women at all stages of the peace process, at both the local and national levels, and to ensure that any resulting peace agreement guarantees the protection and promotion of women's rights in accordance with the constitution and international obligations of Afghanistan."
Khalilzad said last month he hopes a final peace deal can be clinched before Afghanistan's presidential election in July, in which 18 candidates are vying to lead the country, including current President Ashraf Ghani and Chief Executive Abdullah Abdullah.
Guterres noted "the perceived mismanagement" and "allegations of fraud and corruption" in October's parliamentary elections, and stressed the importance of finalizing the results so a new parliament can be inaugurated.
As preparations continue for presidential and provincial and district council elections in July, the U.N. chief also urged all parties not to interfere in the electoral process "and to acknowledge their collective and individual responsibility to ensure that future elections are credible and legitimate."