ALEXANDRIA, Egypt (UPI) — Hopes that the 10 Nile Basin countries would sign a water-sharing agreement at a meeting in Alexandria to settle one of the planet’s most contentious water issues have been dashed — for now at least — after Egypt and Sudan rejected any cuts in their traditional quotas.

But the prospects of a long-term accord on an equitable share-out of the waters of the 3,470-mile Nile, the world’s longest river, remain dim, largely because Egypt, the largest user, refuses to surrender its veto powers and its historic rights over the river that has been its lifeblood since time immemorial.

The Nile and its tributaries flow through Egypt, Sudan, Ethiopia, Eritrea, Tanzania, Uganda, Kenya, the Democratic Republic of Congo, Rwanda and Burundi.

The water ministers of these states put off finalizing a treaty for six months when they wrapped up their four-day Alexandria meeting on Tuesday.

In May, the riparian states had drafted a Cooperative Framework Agreement at a summit in the Congo, but Egypt and Sudan refused to sign because it made no mention of their historic claims on Nile water that date back to the colonial era.

Cairo and Khartoum, which do not see eye-to-eye on most things, hailed Tuesday’s postponement. “It’s a big victory,” a senior Sudanese official declared. “They were going to sign the agreement beginning Aug. 1 regardless of Egypt and Sudan.”

The dispute over the Nile’s life-giving waters has stirred resentment and tension for years now. But now the feuding over water appears to be intensifying.

Some international law experts have gone so far as to suggest that if political and diplomatic efforts fail to settle the issue, the use of military force would be the only option.

Others say it is unlikely that any of these states would resort to such extreme action. But the U.N. Development Program recently voiced concern that conflict over shrinking water resources could trigger “water wars” — as has happened before in the arid Middle East.

Climate change in recent years has reduced rainfall, leading to lower water flows in the Nile and jeopardizing hydraulic projects in several states.

Egypt and neighboring Sudan are the Nile’s largest consumers. Egypt, which lies at the end of the river as it flows into the Mediterranean, does not contribute any water to the Nile system.

But it has the largest population — 80.24 million — and the greatest military power among the riparian states and thus the highest demand for water. For Cairo, safeguarding the Nile water is a strategic objective.

The problem stems in large part from the absence of multilateral agreements concerning water-sharing. This is because Egypt has refused to sign any documents that do not recognize its insistence that its needs are paramount.

The only agreement that does exist lies at the heart of the dispute — the 1929 accord between Egypt and Britain, then the predominant colonial power in Africa.

It gave Cairo veto power over upstream projects that could impede the Nile’s flow levels — as Turkey’s current ambitious dam-building program is cutting off the flow of the Tigris and Euphrates to Syria and Iraq.

Britain claimed it had acted on behalf of its African colonies, but its motivation undoubtedly had a lot to do with maintaining strategic control over the Suez Canal to hold its empire together.

A bilateral treaty between Egypt and Sudan in 1959 allocated Egypt 55.5 billion cubic meters of water annually — 87 percent of the Nile’s flow — with Sudan getting 18.5 billion cubic meters.

The other riparian states say this is grossly unfair and demand an equitable water-sharing pact that would allow for much wider irrigation for crop-growing (an increasingly vital issue because of global food shortages) and hydraulic power projects.

Egypt argues that the upstream countries have far greater rainfall than Egypt — which has hardly any — and other sources of water than the Nile.

The river provides 87 percent of Egypt’s water resources. An Egyptian government report in July warned that the country’s water requirements would exceed its resources by 2017.