Bahrain's Foreign Minister Khalid Al Khalifa arrived Sunday in the Iraqi capital Baghdad for an unscheduled visit.
He will meet Iraqi President Fuad Masum and Prime Minister Haidar al-Abadi during his visit, a source with the Iraqi Foreign Ministry said on condition of anonymity because he was unauthorised to speak to media.
The reason for the visit remains unclear.
The visit comes amid a Gulf crisis after Saudi Arabia, Egypt, the United Arab Emirates and Bahrain cut diplomatic relations with Qatar.
The four countries accuse Qatar of meddling in their affairs and supporting terrorism, a claim denied by Doha.
The four have imposed a sea, land and air embargo on Qatar and presented a list of demands for Doha or face further sanctions.
Qatar contends that the blockade is in violation of international law.