The planned summit Tuesday between Bashir and Kiir was called to mediate differences between the two countries over oil and security issues, the Sudan Times reported Tuesday.
The countries have been negotiating under a U.N. Security Council deadline of Thursday to resolve a number of issues -- including transportation of oil from the South through Sudan, disputed border regions and citizenship -- that have risen since South Sudan became independent of Sudan in last July.
The Sudanese Foreign Ministry said in a statement Monday evening Bashir declined an invitation by the African Union chief mediator to meet Kiir "due to previous engagements."
Bashir was scheduled to go to Doha, Qatar, Tuesday to meet with Emir Hamad bin Khalifa al-Thani.
"The government prefers to hold such a summit after good preparation and arrangements," the ministry statement said, explaining any summit called to resolve the lingering issues should end with a positive result.
The countries face a Thursday deadline to comply with U.N. resolution 2046, which, among other things, calls for an end to the fighting between the two countries, a resumption of negotiations under the auspices of the African Union and a time frame to conclude the talks.
U.S. Secretary of State Hillary Clinton will visit South Sudan as part of her trip Africa beginning this week to "encourage progress," the Sudan Times said.
Clinton, the most senior U.S. official to visit South Sudan since it gained independence last year, will meet with Kiir to "reaffirm U.S. support and to encourage progress in negotiations with Sudan to reach agreement on issues related to security, oil and citizenship," the State Department said.
Clinton's trip to Africa began Tuesday and will run through Aug. 10. It also includes visits to Senegal, Uganda, Kenya, Malawi and South Africa.