Omar al-Bashir was charged by the International Criminal Court with war crimes in connection with armed conflicts between the independent state of South Sudan and Sudan.
Still, he ruled out the use of American military force in connection with the conflict.
The ICRC also says that recent months have seen an increase in the number of people arrested in connection with the conflict.
The United Nations Human Rights Council appointed a widely respected Jewish South African judge on Friday to lead a high-level mission to investigate allegations of war crimes committed by Israel in connection with the conflict in the Gaza Strip that ended Jan . 18
"In terms of the whole diplomatic rounds the prime minister has been making in connection with the conflict, there is obviously a close alliance with Washington throughout," a spokeswoman for the prime minister's office said.
The Turan news agency, quoting the ministry of internal affairs, said the detention was "in connection with the conflict he had stirred with the staff of the border service".
The issue comes up most often in connection with the conflict between Israel and the Palestinians, and to the dismay of supporters of Israel — and sometimes supporters of the other side, denouncing Israeli military actions — The Times is sparing in its use of "terrorist" when reporting on that complex struggle.
The draft defines foreign terrorist fighters as "individuals who travel to a state other than their states of residence or nationality for the purpose of the perpetration, planning, or preparation of, or participation in, terrorist acts or the providing or receiving of terrorist training, including in connection with armed conflict".
In May, he became the first person in the UK to be convicted of terrorist offences in connection with the conflict in Syria.
Last month, a 31-year-old man from Portsmouth became the first person in the UK to be convicted of terrorist offences in connection with the conflict in Syria.
