JUBA, Sudan South Sudan's president on Saturday urged southerners to vote for independence in a referendum if they wanted to be free, the closest he has come to calling publicly for the separation of the oil-producing region.
The south secured a vote on whether to break away from Sudan as part of a peace deal that ended more than two decades of war with the north. But until now, southern President Salva Kiir has stuck to the official line of building support for unity.
"When you reach your ballot boxes the choice is yours: you want to vote for unity so that you become a second class in your own country, that is your choice," he told a congregation in a cathedral in the capital Juba during a service to launch a prayer campaign for elections in 2010 and a referendum in 2011.
"If you want to vote for independence so that you are a free person in your independent state, that will be your own choice and we will respect the choice of the people."
The comments will add pressure to the already troubled relationship between Kiir's Sudan People's Liberation Movement (SPLM) and the north's dominant National Congress Party (NCP).
Both sides promised to build up a campaign to make the unity of Sudan attractive to voters when they signed the 2005 Comprehensive Peace Agreement that settled the civil war.
Most southerners, embittered by the long war and the lack of development in the south since it ended, are widely thought to support independence. But their leaders have so far not gone as far as openly saying they want to split.
The bulk of Sudan's proven oil reserves are in the south, while refineries and Sudan's only port are in the north.
No one from the NCP was immediately available to comment.
Political tensions are rising in Sudan ahead of the first multi-party election in more than 20 years, promised under the peace deal and are due to take place in April 2010.
Voter registration was due to start on Sunday.
The United Nations said it was preparing to make Sudan's biggest delivery of election materials to help in the exercise.
"There may be some difficulties moving materials to very remote locations," said one U.N. official.
Kiir spoke out as the U.S. envoy to Sudan Scott Gration flew into Juba at the start of two days of talks with the southern leadership.
Gration has been holding meetings with northern and southern leaders, urging them to resolve sticking points in the peace deal including the details of the referendum, the constituencies for the election and the position of the north/south border.
Sudanese officials said he was due to visit Khartoum on Monday and Tuesday.
U.S. President Barack Obama launched a new carrot-and-stick policy this month aimed at ending violence in Sudan's Darfur region and the semi-autonomous south.
Two million people were killed and 4 million fled their homes between 1983 and 2005 as Sudan's north and south battled over differences of ideology, ethnicity and religion. North Sudan is mostly Muslim while southerners are largely Christian and followers of traditional beliefs.
(Reporting by Jose Vieira, additional reporting by Skye Wheeler, writing by Andrew Heavens; Editing by Diana Abdallah)