United Nations Secretary General Antonio Guterres condemned late Sunday the terror attack at an Istanbul nightclub that killed 39 people and injured 69 others.

Guterres "extends his deepest condolences to the families of the victims and expresses his solidarity with the Government and people of the Republic of Turkey and of those countries whose nationals were impacted," a statement from his office said.

The UN Security Council earlier condemned "in the strongest terms the heinous and barbaric terrorist attack".

"The members of the Security Council reaffirmed that terrorism in all its forms and manifestations constitutes one of the most serious threats to international peace and security,” the statement added, urging member states to cooperate with Turkey.

Leaders from around the world issued messages of condemnation and solidarity after the attack, which hit the country just an hour after New Year celebrations early Sunday.

Istanbul Governor Vasip Sahin described the attack in Ortakoy as “cruel” and an “act of terror”.

“At 1.15 a.m. [2215GMT], a terrorist carrying a long-barreled weapon martyred the police officer waiting outside, and then martyred another citizen" to enter the club, he said.

“He then carried out this violent and cruel act by spraying bullets on innocent people who were celebrating the New Year," Sahin added.

Police have launched an operation to catch the suspect.

Meanwhile, thirty-eight victims have been identified, Turkish justice ministry sources said late Sunday.

Eleven of the dead were Turkish nationals and one was a Turkish-Belgium dual-national, the sources said.

Seven victims were from Saudi Arabia and had traveled to Istanbul just for celebrations. Three of the dead were from Lebanon and Iraq each.

Two nationals from Tunisia, India, Morocco and Jordan were killed, and Kuwait, Canada, Israel, Syria and Russia lost one citizen in the attack.

One victim remains unidentified.