UN Director-General Sergei Ordzhonikidze said Friday that calls for jihad by a head of state were unacceptable, after Libyan leader Moamer Kadhafi made such a call against Switzerland.
Asked by journalists about one state calling for jihad against the other, Ordzhonikidze said: "I believe that such declarations on the part of the head of state are inadmissible in international relations.
"I'm not even talking about actions," he added.
Kadhafi turned up the heat in his country's dispute with Switzerland on Thursday, calling for jihad over a recent Swiss ban on the construction of minarets.
"Jihad against Switzerland, against Zionism, against foreign aggression is not terrorism," Kadhafi said in a speech in the city of Benghazi to mark the birthday of the Muslim prophet Mohammed on Friday.
With the UN's European headquarters located within Switzerland, Ordzhonikidze pledged to do "all" to prevent any attacks on its premises.
"I hope we will prevent any attempt. Our security has all the power, and knowledge and training to prevent any attempt to violate the security of the UN premises. So you may be rest assured," added the head of the European headquarters.
Kadhafi spoke at a delicate point in relations with Switzerland, which soured in July 2008 when Kadhafi's son Hannibal and his wife were arrested and briefly held in Geneva after two domestic workers complained they had mistreated them.
The row escalated when Libya swiftly detained and confiscated the passports of two Swiss businessmen, Rashid Hamdani and Max Goeldi. It deepened again last year when a tentative deal between the two countries fell apart.
Both men were convicted of overstaying their visas and of engaging in illegal business activities.
Hamdani's conviction was overturned in January, and he has now returned home, while Goeldi surrendered to authorities this week and is now serving a reduced sentence of four months.
The Libyans and Swiss and have been holding talks, with Switzerland seeking Goeldi's release, while both countries impose visa restrictions.