A prosecutor at the International Criminal Court is expected to seek an arrest warrant Monday charging President Omar al-Bashir with orchestrating violence in Darfur that has left hundreds of thousands of people dead since 2003.
The statement from Mr. Bashir's National Congress Party called the case against the Sudanese leader "irresponsible cheap political blackmail" that has no legal basis.
Bashir huddled with cabinet ministers and advisers Sunday, weighing how the government would response to the ICC if the president is indicted.
Sudan has also asked the Arab League for an emergency meeting of Arab foreign ministers.
One of the participants at the cabinet meeting, Essam Youssef, told reporters afterward that Sudanese politicians agreed to send "a strong message to the international community that we stand with all our power against anybody ... who seeks to impose sanctions or target our head of state."
"This action violates Sudan's sovereignty and its people's values and dignity," said Mr. Youssef, an ally of Bashir who heads the country's Muslim Brotherhood movement.
On Saturday, a government spokesman said Bashir's indictment would be "disastrous" for the region and could affect the work of humanitarian organizations in Sudan.
Mahjoub Fadul Badry did not specify what actions might be taken, but there are fears the charges could provoke reprisals against international aid workers and the United Nations-African Union (UNAMID) peacekeepers that are already experiencing difficulties in doing their work.
A UN spokeswoman said Sunday that the peacekeeping force was on security alert but still relying on the Sudanese government for protection inside the country.
Some foreign staff not directly working on emergency or humanitarian relief operations could be "temporarily relocated," said Shereen Zorba, deputy UNAMID spokeswoman.
Ms. Zorba stressed that any disruption to humanitarian work in Darfur could have disastrous consequences.
"The people of Darfur have already suffered unimaginable suffering and should not be subjected to more tragedy," she said.
Seven UNAMID peacekeepers were killed Tuesday when heavily armed fighters attacked them while they were on a patrol in northern Darfur. More than a dozen other peacekeepers were injured in the ambush – the deadliest against the joint UN-AU force since it deployed in the remote western Sudanese region earlier this year.