By Liz Blunt BBC Africa analyst

Sudan's Vice President, Ali Uthman Muhammad Taha, says he expects a ceasefire with the Sudan People's Liberation Army (SPLA) to take place within weeks.

It should be a matter of weeks, if people are serious

Sudanese vice president

The government and the southern rebel movement achieved the first stage of a peace agreement in Kenya last weekend, but a number of difficult issues remain to be resolved.

Since the announcement of the peace accord, the Sudanese Government has been on a charm offensive - sending its emissaries round the world to urge its friends to support and invest in the new, peaceful Sudan.

"It should be a matter of weeks, if people are serious," Mr Taha said.

Dividing oil riches

Issues still to be tackled include the practicalities of power-sharing during the next six years.

It is still unclear how the country's oil wealth - largely derived from the south - will be divided.

The actual ceasefire will not take effect until the end of the process.

But the vice president said he believed that everything else could be quickly settled, now that agreement had been reached on the issue of religion.

At the end of six years the agreement provides for a referendum on whether the south should remain part of Sudan or become independent.

Honouring promises

Mr Taha said the government's priority was for a solution within a united Sudan, and the agreement itself made it clear that unity was the preferred option.

"The framework of the protocol is very specific in giving unity a priority.

"So whoever speaks in favour of unity, would be reflecting the spirit of the framework. This does not negate or marginalise that there is another option."

The government's job now, he said, was to work to make unity attractive.

But he said if they failed, and there was finally a vote for secession, then the government would honour the agreement and let the southerners go their own way - taking their oil wealth with them.