The UN Security Council has reiterated its call for the rebel-held Yemeni port of Hudaydah to remain open after urgent talks on the Saudi-backed offensive.
However, the council rejected a call by member state Sweden for an immediate halt to hostilities.
Pro-government forces backed by a Saudi-led coalition launched the offensive after Houthi rebels ignored a deadline to leave the port city.
Hudaydah is a key entry point for humanitarian aid to war-torn Yemen.
Calm before the storm
By Victoria Bisset, BBC News
In Hudaydah, as in towns and cities across Yemen, the war has affected all aspects of life since it began in 2015.
Yemen was already among the poorest Arab nations, and the conflict is now threatening one of its most populated cities.
Much of the country's food and medical supplies travel through the port city, making the situation even worse for the millions facing starvation.
Although military operations have not yet reached inside the port city, the sounds of aircraft circling overhead can be heard and residents are tense, a local journalist told the BBC.
The UN Security Council met in a closed-door session on Thursday amid fears that the fighting could result in…