SANAA, Yemen (AP) — The United Nations humanitarian coordinator for Yemen said Saturday that they are seeking ways to ensure unconditional access to Taiz, a city of about 25,000 residents besieged by Shiite rebels who control the capital and have been fighting an internationally recognized government.

"Only a few shops are open. Food and other basic goods needed to survive are in short supply. Basic services are scarce, including access to water and fuel," UN humanitarian coordinator Jamie McGoldrick said in Sanaa, the capital, following a visit to Taiz.

"Humanitarian access to three districts within the city has been difficult for many months," while hospitals haven't been spared the violence, said McGoldrick.

Taiz has been besieged for months by Shiite rebels known as Houthis who have been indiscriminately shelling the war-devastated city and blocking the delivery of humanitarian aid, according to residents and aid groups.

World Food Program Deputy Director Adham Musallam said they managed to bring in enough food supplies for three thousand families in the city

Taiz, which lies on the border between northern and southern Yemen, could be a major turning point in Yemen's civil war, potentially cementing the Houthis' loss of Yemen's south.

UNICEF's representative in Yemen, Julien Harneis, said about 1,900 children were either killed or injured since the conflict began, with most of the current deaths in the provinces of Taiz and in Saada, the Houthis' main stronghold.

White House National Security Council Spokesperson said the United States was concerned "about the terrible violence impacting civilians in Taiz" and the need to allow the unimpeded delivery of humanitarian aid to all Yemenis in need. He said in a statement that the recent progress in improving humanitarian access to parts of Taiz "needs to be replicated across the entire city."

Yemen's civil war began when the Houthi rebels, allied with a former Yemeni president, overran the capital in September 2014. In March 2015, a coalition of countries led by Saudi Arabia began airstrikes and later, a ground operation to retake the country. More than 5,800 people have been killed and over 80 percent of Yemen's population is in dire need of food, water and other aid, according to the United Nations.