GENEVA (Reuters) - The United Nations refugee agency appealed to all sides in Syria on Friday to provide safe passage for 140,000 civilians displaced by fighting in the southwest so that they can receive aid and shelter.

The UNHCR also said it was ready to discuss with Syria and Russia their plan to set up centers for returning Syrian refugees. It stressed that any returns must be safe and voluntary in line with international standards.

Nearly 13,000 Syrian refugees in neighboring countries returned to their homeland in the first half of 2018, along with 750,000 internally displaced, UNHCR spokesman Andrej Mahecic told a Geneva news briefing.