UNITED NATIONS — The United Nations secretary-general is again urging factions in conflict to heed his call for a global cease-fire to help tackle the COVID-19 pandemic.

In a report to the U.N. Security Council released Thursday, Antonio Guterres pointed to the more than 20,000 civilians killed or injured in 2019 attacks in 10 countries — and millions more forced from their homes by fighting. He said the pandemic is “the greatest test the world has faced” since the United Nations was established 75 years ago and has already had a severe impact on efforts to protect civilians, especially in conflict-affected countries where weak health care systems can be overwhelmed.

The U.N. chief said support for his March 23 cease-fire appeal from governments, regional organizations, armed groups, civil society and individuals throughout the world has been “encouraging” — but he said in many instances “challenges in implementing the cease-fire still need to be overcome.”

Guterres reiterated his global cease-fire call, saying “as the world confronts the monumental challenge of the COVID-19 pandemic, the need to silence the guns could not be more acute.”

He issued the appeal in his annual report to the Security Council on the protection of civilians where he stressed that the most effective way to protect them “is to prevent the outbreak, escalation, continuation and recurrence of armed conflicts.”