The UN envoy to Yemen said Thursday he was engaged in talks with the country’s warring parties to secure a nationwide ceasefire to help counter the threat of the coronavirus.

Martin Griffiths’ office said he is discussing “concrete steps” with the warring sides despite a recent escalation in the long conflict.

Yemen has so far not recorded any case of COVID-19, but aid groups are concerned that when or if it does hit, the impact will be catastrophic for a country already facing what the UN calls the world’s worst humanitarian crisis.