Bashir, who will head Sudan's delegation, is due to arrive in Istanbul later on Monday to take part in the Turkish-African summit August 19-20, a Turkish Foreign Ministry official told Reuters.

International Criminal Court Chief Prosecutor Luis Moreno-Ocampo last month asked the court to issue an arrest warrant for Bashir on charges of genocide, war crimes and crimes against humanity in Darfur, saying his state apparatus had killed 35,000 people and indirectly at least another 100,000.

Asked about the possibility of an ICC warrant being issued while Bashir is in Istanbul, a Turkish Foreign Ministry official declined to speculate on what Turkey would do.

"Bashir was invited to the summit as an African country leader and there is no arrest warrant against him at his moment. If there are any requests, we will evaluate them then," the official said.

NATO-member Turkey has not ratified the treaty forming the ICC but is under pressure to become a member as part of negotiations to join the European Union.

ICC judges could take weeks or months to issue a warrant, but have never failed to issue one after it was requested by the prosecutor. The court returned from recess on Monday.

International experts estimate some 200,000 people have died and 2.5 million driven from their homes since mostly non-Arab rebels took up arms in early 2003 accusing central government in Khartoum of neglect. Sudan blames the Western media for exaggerating the conflict and puts the death toll at 10,000.

CONCERN

U.S.-based Human Rights Watch said on Friday it was "concerned" by Turkey's decision to welcome Bashir, who is expected to hold bilateral meetings with Turkish President Abdullah Gul and Prime Minister Tayyip Erdogan on the sidelines of a summit focusing mostly on energy and trade.

"The Turkish government should reject efforts by Sudan's President Omar Bashir to secure a suspension of the International Criminal Court's investigation against him," Human Rights Watch said in a statement.

"Turkey should also convey a clear message that Khartoum must not respond to the investigation with retaliation against civilians, peacekeepers, or humanitarian workers."

The summit in Istanbul is expected to be attended by leaders from 40 African countries, as energy-thirsty Turkey seeks to tap into the African continent's vast resources.

Turkey, which has signed liquefied gas agreements with Algeria, is seeking to boost investments and trade with sub-Saharan Africa, following similar moves by emerging powerhouses China and India.

Turkey has 12 embassies in the continent and plans to increase the number to 27 through next year.

"In recent years the continent became the focus of attention of several countries like China, India and Japan because of its rich energy and mining resources," a Foreign Ministry official said.

"It is Turkey's obligation to increase deals with Africa from the perspective of historical ties and fulfilling the potential of the continent."