The ecumenical aid group ACT Alliance has hailed a renewed pledge by opposing parties in the South Sudan conflict to secure humanitarian access to provide aid for the hundreds of thousands of displaced people within the country as a step forward.

"This agreement comes at a critical time when only a small window of opportunity remains to get relief goods to those in need in remote areas," said ACT Alliance general secretary John Nduna in a statement Wednesday.

Separately Amnesty International said in a report Thursday that both sides in the conflict have flouted international law and shown no regard for human rights.

"The conflict in South Sudan has devastated the lives of millions of people. Since the outbreak of violence on 15 December 2013, forces fighting on behalf of the government and those allied with the opposition under the leadership of former Vice President Riek Machar have shown a total disregard for international human rights and humanitarian law.

"They have deliberately killed civilians; executed captured fighters; abducted and sexually assaulted women and girls; arbitrarily detained civilians, some of whose whereabouts are still unknown; burned down homes; damaged and destroyed medical facilities; and looted public and private property as well as food stores and humanitarian aid."

Amnesty said about 950,000 people are displaced within South Sudan, and a further 290,000 have fled to neighbouring countries. "About 80,000 displaced people are living in "protection sites" in the United Nations Mission in South Sudan (UNMISS) bases, where there are serious health and security concerns."

The government in South Sudan said Wednesday it would suspend attacks on rebel forces for one-month following international pressure for an end to an inter-ethnic conflict that has raised fears of genocide in the world's newest country.

'MONTH OF TRANQUILITY'

South Sudan's Information Minister Michael Makuei Lueth said the government would honor a "month of tranquillity", proposed on Monday at peace talks in Ethiopia, but that the army could still fight back if attacked.

"We have already given our forces an order," Lueth said in the Ethiopian capital Addis Ababa, following months of peace talks.

Nduna said, "The rains have already started, and within one month access to these areas will no longer be possible for those displaced by the fighting and unable to continue with their livelihoods which will have a negative impact in the much longer term.

"It is absolutely urgent for the government and opposition to do their utmost to open humanitarian corridors within South Sudan and from neighbouring countries to aid to those in need."

He was speaking after an ecumenical delegation visited the country last week to appeal for secured humanitarian aid access and an end to the violence.

A high-level delegation of faith leaders, from the World council of Churches, including ACT Alliance, met with church leaders and government officials from South Sudan last week.

The delegation urged the parties to meet face to face, agree a ceasefire and guarantee aid agencies access to civilians in hard-to-reach and volatile areas.

Nduna said the agreement signed this week by the warring parties to facilitate and support humanitarian assistance shows there is a degree of clear political will to negotiate and reach a solution.

The agreement entitled a "Recommitment on Humanitarian Matters" relating to the conflict, was signed by representatives of South Sudan President Salva Kiir and opposition leader Riek Machar on May 5.

It is a recommitment to the Cessation of Hostilities agreement signed between the South Sudan government and the opposition on January 23, but has been largely ignored by the two factions.

It states that parties will "consider one month of tranquillity from 7 May to 7 June 2014 in order to preposition humanitarian supplies and enable the people of South Sudan to plant their food crops, care for livestock and move to areas of safety."

Since the violence broke out in December 2013, ACT Alliance, which includes churches inside the World Council of Churches, has worked to get life-saving relief supplies to thousands of people in South Sudan and for those crossing the border into Ethiopia, Kenya and Uganda.

The Intergovernmental Authority on Development that is facilitating the peace negotiations said President Kiir and Machar will meet face-to-face on Friday for further talks.

"We hope that this meeting will mark the end of the violence and the start to a process of peace and reconciliation," Nduna said. "And we call on the president and the opposition to this time adhere to the Recommitment on Humanitarian Matters.

"Peace is only possible if these two commit to immediately resolving their political differences and embarking on a process of national reconciliation and healing."