President Barack Obama on Friday will urge Iran to come clean about its nuclear activities amid reports that Tehran is building a secret underground plant to manufacture nuclear fuel, officials told NBC News.

The administration wants to ratchet up pressure on Iran on the eve of talks set for next week and make clear that Tehran has not been forthcoming about its nuclear activities, officials said.

Senior administration officials noted that the nuclear non-proliferation treaty requires countries to disclose such facilities at the beginning of construction. This facility, known as the “Qum facility,” would also be in violation of U.N. resolutions requiring Iran to halt enrichment activities.

Obama, along with British Prime Minister Gordon Brown and French President Nicolas Sarkozy, will make the information on the covert facility public at around 8:30 a.m. ET, before the opening of the Group of 20 economic summit in Pittsburgh.

Iran revealed the existence of the plant earlier this week in a letter sent to Mohamed ElBaradei, chief of the International Atomic Energy Agency, officials told The Associated Press.

It had previously said it was operating only one plant, which is being monitored by the IAEA.