The United Nations Security Council has issued another call for Yemen's ports to remain open for food and aid deliveries. UN officials and Security Council diplomats are concerned about the humanitarian crisis in the country. Our UN correspondent Liling Tan has details from New York.

LILING TAN NEW YORK "After earlier diplomatic attempts to prevent the assault failed, and with an Arab-led offensive now well underway, the UN Security Council on Thursday delivered a unified plea to keep critical entry points in the Yemen port city of Hodediah open for crucial food and aid supplies for civilians."

Emerging from an emergency closed-door session, Russian Ambassador Vassily Nebenzia, the president of the Security Council this month, delivered the Council's position.

VASSILY NEBENZIA RUSSIAN AMBASSADOR TO UN "They were united in their deep concerns about the risks to the humanitarian situation and reiterated their call for the Ports of Houdeidah and Saleef to be kept open."

Hodeidah is home to Yemen's largest port, where most of the impoverished, conflict-torn country's imported supplies arrive, including food, medicine and fuel. It's also a lifeline for humanitarian aid. Right now, UN and aid agencies are said to be rushing humanitarian assistance to some 600 thousand civilians in Hodeidah in the midst of the offensive. UN envoy to Yemen Martin Griffith has been working on a framework for negotiations between the warring sides.

But while Security Council diplomats are pushing for an end to the violence and a resumption of dialogue, they remain cautious about taking sides. 

The U.S., in particular, has come under some criticism over its support of the coalition, but the Pentagon on Thursday denied any military involvement in the Hodeidah offensive. 

Pentagon spokesman Major Adrian Galloway said the U.S. support is for logistics, and not combat, and that it involves aerial refueling for coalition aircraft and intelligence assistance in protecting borders from Houthi attack. He added the U.S. supports the UN envoy to Yemen in his mediation efforts. Liling Tan, CGTN, New York.