(Image: Wikimedia Commons)

The United Nations has asked member states to "respect" its privacy amid reports it had been extensively spied on by the US government.

Almost exactly two years after it emerged that the National Security Agency was conducting surveillance on the United Nations, a report published in tandem by The New York Times and ProPublica added new details.

Documents provided by Edward Snowden showed the US government was getting help from AT&T, which supplied the United Nations' headquarters in New York with internet and phone services.

The report said AT&T's alleged relationship with the NSA under the "Fairview" program helped the intelligence agency tap into phones, emails, and infiltrate the video-conferencing systems. Earlier reports said UN secretary-general Ban Ki-moon's talking points to President Barack Obama were were also seen through the Blarney email-grabbing program.

The United Nations, the global governing body for the world's governments, is examining "how best to respond," UN spokeswoman Vannina Maestracci told reporters on Monday.

According to a Reuters report, Maestracci said the US had "previously given us assurances as to the fact they are not and were not monitoring our communications," after the intelligence agency was found spying in 2013, thanks to documents provided by Snowden.

"The inviolability of the United Nations is well established under international law and we expect member states to act accordingly and to respect and protect that inviolability," said Maestracci.

US surveillance of the United Nations and its diplomatic missions could be in breach of the 1961 Vienna Convention, an international agreement governing diplomatic relations.