(Adds Bush calling for ceasefire during peace talks)
By Opheera McDoom
KHARTOUM, Sept 25 (Reuters) - Darfur rebel leader Khalil Ibrahim said on Tuesday he would carry on fighting during upcoming peace talks until a final settlement is reached to end the conflict in western Sudan.
His comments came despite intense international pressure to end the fighting in Darfur where experts say 200,000 people have been killed and more than 10 times as many forced to flee their homes in fighting since 2003.
At the United Nations Security Council, U.S. President George W. Bush called on the rebels and Sudanese government to observe a cease-fire during peace talks set for Oct. 27 in Libya and urged fast action to end what he called "genocide".
"My nation has labeled what's taking place in Darfur as genocide and when you find genocide it's time to do something about it," Bush said. "Time is of the essence."
But Ibrahim, whose Justice and Equality Movement (JEM) has been the mainstay behind clashes with the army in eastern Darfur in recent months, said he would attend talks but not lay down arms.
"We will not cease fire before we reach a political settlement," Ibrahim told Reuters from Darfur. "Ceasing fire is a termination of the resistance and revolution."
Sudanese President Omar Hassan al-Bashir said this month he would observe a ceasefire in Darfur when the talks begin.
But Ibrahim called that "a trick" and said the three rebel movements that negotiated in previous talks until May 2006 had abided by an earlier truce, which the government violated.
Only one faction signed the 2006 peace deal, which has been rejected by many in Darfur as inadequate.
Since then the rebels have split into more than a dozen rival groups. But a recent military alliance between JEM and Sudan Liberation Army (SLA) Unity faction has made them the biggest military threat to Khartoum in Darfur.
SANCTIONS THREAT
In a sign of further rebel splits, Ibrahim also said he was dismissing his deputy and veteran of the conflict, Bahr Idriss Abu Garda, accusing him of secret meetings with the government to undermine the movement.
"He is working together with the government," he said.
Mediators have described government attempts to negotiate deals with individual commanders as "unhelpful" as rebels worked to reach a common platform ahead of peace talks.
SLA founder and chairman Abdel Wahed Mohamed el-Nur has said he will not attend peace talks until there is security on the ground. He has few troops in Darfur but commands massive popular support, especially among Darfur's largest Fur tribe.
U.S. Deputy Secretary of State John Negroponte has threatened sanctions for those who do not attend talks. Ibrahim, who himself has been sanctioned by Washington, dismissed the threat.
"The United States doesn't have carrots for us -- only sticks," he said. "They should know by now that when they threaten they only complicate the situation."
"They should stop the threats. It will not help peace."
Nur said his movement stood for democracy and hoped Washington would support them in a positive role in Darfur.
"I hope that Negroponte's words do not reflect the policy of the U.S. government," he told Reuters.
Nur criticised African Union Commission Chairman Alph Oumar Konare, who U.N. officials said had rejected non-African battalions offered for a 26,000-strong join U.N. AU force to stem the Darfur violence.
"Everyday he's arguing this and delaying the mission my people are being raped and killed," he said, adding the AU force now there lacked the equipment and logistics to do the job.
AID ATTACK
Khartoum rejects estimates by international experts who say some 200,000 people have died in the 4 1/2-year conflict. It says the West exaggerates the toll and puts it at 9,000.
Factionalised rebels and tribal militia infighting has also caused security chaos in Darfur, where the world's largest aid operation helps more than 4 million people.
In Zalengei in West Darfur, three Norwegian Church Aid workers were kidnapped on Sunday by Arab nomads who demanded blood money for three of their tribesmen killed inside the town.
One NCA official in Zalengei told Reuters the three Sudanese workers had been released into police custody for their own safety and planned to leave on Wednesday.
He said shots were fired overnight at the U.N. security office in Zalengei and aid agencies were discussing whether it was safe to continue working in the town.
On Monday British aid agency Oxfam warned it may consider withdrawing from Darfur if the security situation worsened.
