NAIROBI - International humanitarian agencies say a truce to end fighting in Ethiopia's war-ravaged Tigray region has yet to deliver the resumption of aid, as the United States urged Addis Ababa to respect the agreement and allow assistance.

Under a ceasefire agreement signed Nov. 2 between Ethiopia's government and the Tigray People's Liberation Front (TPLF), the party that controls Tigray, the federal government pledged to work with humanitarian agencies to expedite the provision of aid, without committing to a specific timeline.

Ethiopia's government denies blocking aid, and on Friday its chief negotiator said essential services were being restored and humanitarian aid was flowing into the region of some 5.5 million people, half of them in severe need of food after the two-year conflict.

The two sides are currently negotiating implementation of that agreement, including the resumption of aid deliveries.

International aid agencies say they have been blocked from sending assistance into Tigray for much of the conflict.

Three officials at international humanitarian organisations said that despite the truce their convoys were still waiting for permission from authorities to cross into the area.

The U.S. State Department's Bureau of African Affairs urged a swift resolution.

"Vulnerable Ethiopians in Tigray, Afar, and Amhara need aid now," it said on Twitter, referring to the neighbouring regions impacted by the war. "Waiting urgently for actions to respect and implement the agreement."

It also Ethiopian government's lead negotiator, Redwan Hussien, as saying during ongoing talks in Nairobi that aid would flow unhindered "by week's end".

Redwan insisted on Friday that there was "no hindrance whatsoever regarding aid."

"Aid is flowing like no other times," he said on Twitter, adding that 35 trucks with food and three trucks with medicine had arrived in the northern city of Shire and services were being reconnected.

Another official familiar with the humanitarian situation said, however, Redwan may have been talking about Ethiopian trucks, while international agencies could not move freely.

Redwan did not respond to a request for comment.

Ethiopia's National Disaster Risk Management Commission, which coordinates Ethiopian aid, said it would provide an update later on Friday.

The UN's Office for the Coordination of Humanitarian Affairs in Ethiopia did not respond to a request for comment.

Against this backdrop, the African Union-mediated talks between Ethiopia's government and representatives from Tigray continued in Nairobi on Friday, with military commanders trying to work out details of the disarmament of Tigray forces, resumption of aid deliveries among other measures.

Observers have expressed concerns about when Eritrean and other forces that were not party to the ceasefire will withdraw. Eritrea's government has said nothing about whether it would withdraw its troops and abide by the ceasefire agreement.

(Reporting by Tommy Reggiori Wilkes and Ayenat Mersie; Editing by James Macharia Chege and Tomasz Janowski)