Sudanese officials said they were seeking broader international support to stymie any arrest warrant.
"Contacts are already established with China and Russia . and they have shown their support . But it's informal so far," said one senior government source on condition on anonymity.
One option before the U.N. Security Council is to use Article 16 of the ICC's statute to suspend a prosecution for a year, but the European envoy who spoke to Reuters on Friday was sceptical the council would do that.
"China is reflecting on Article 16, but I think the position of most Western countries will be to support the court," he said.
ICC Prosecutor Luis Moreno-Ocampo is due to submit to judges "evidence on crimes committed in the whole of Darfur over the last five years" and seek to charge an individual or individuals, a prosecution statement said on Thursday.
It gave no details. The Washington Post quoted U.N. officials and diplomats as saying the prosecutor would charge Bashir with genocide and crimes against humanity on Monday.
Moreno-Ocampo said last month that Sudan's "entire state apparatus" was involved in an organised campaign to attack civilians in Darfur and said he would present judges with evidence implicating senior Sudanese officials in July.
"This is a new world age - it will send a message that anyone who commits crimes and genocide will be judged," said Abdel Wahed Mohamed el-Nur, founder of the Darfur rebel Sudan Liberation Movement (SLM).
Nur and two other rebel leaders told Reuters that if Moreno-Ocampo indicted any of their own commanders, they would comply and send them to the ICC in The Hague for trial.
Moreno-Ocampo has said he was investigating a 2007 attack on an African Union base in Haskanita in Darfur which killed 12 peacekeepers and was blamed on rebels.
ICC judges issued arrest warrants for two Sudanese suspects last year - government minister Ahmed Haroun and militia commander Ali Kushayb. Khartoum has refused to hand them over.
International experts say at least 200,000 people have died in Darfur and 2.5 million have been displaced since a rebellion erupted in 2003. Khartoum says 10,000 people have been killed.
