Libya has postponed a landmark election until next month to give the nation more time to prepare for its first vote since last year's ouster of longtime dictator Moammar Gadhafi in an armed rebellion.

The U.N. mission in Libya praised the decision to switch the election for a national assembly from the original date of June 19 to July 7, saying it will “enable essential preparations to be completed prior to voting.” In a statement issued Sunday, U.N. envoy Ian Martin said Libya's election commission has made “admirable” progress in the context of what he called “an extremely tight timetable and major operational challenges.”

Libyan election commission chief Nouri Al-Abbar said the 18-day postponement is needed to give voters more time to register and to give authorities more time to examine the qualifications of candidates. Speaking at a Tripoli news conference, he said his commission only started work in February, giving it a short time to organize the country's first national election in more than four decades.

Other challenges facing the election organizers include Libya's lack of an effective bureaucracy and poor security in parts of the country.

The vote is meant to produce a national assembly that will write a new Libyan constitution and form a government to replace the unelected National Transitional Council that took over from Gadhafi.

Libya says 80 percent of eligible voters have registered for the election so far, equivalent to 2.7 million people. Dozens of new political parties have been formed to contest 80 of the assembly's 200 seats. The other 120 seats are reserved for independent candidates.

Martin said he has confidence in the commitment of Libyan authorities to see an “early and successful conclusion of the electoral process.”