U.N. Secretary-General Ban Ki-moon arrived in Baghdad Monday for talks with Iraqi Prime Minister Haider al-Abadi and other top officials.
He is also due to meet President Fuad Masum, Foreign Minister Ibrahim al-Jaafari and parliament speaker Salim al-Juburi.
The U.N. mission in Iraq announced Ban's arrival on Twitter but provided no details of the agenda of the talks.
Iraqi forces are battling to retake the city of Tikrit, the government's largest military operation yet against the Islamic State jihadist group.
The fact that Baghdad is receiving military assistance from both the United States and Iran, however, has created tensions, internally and internationally.
Ban flew in from Egypt, where he attended an Arab League summit in Sharm el-Sheikh dominated by Saudi-led military action against Yemen's Huthi Shiite rebels.
He is expected to travel on to Kuwait for a meeting of international donors on Tuesday called to address a massive funding gap in the response to the conflict in Syria.