WASHINGTON  The Obama administration plans to tell Iran this week that it must open a newly revealed nuclear enrichment site to international inspectors “within weeks,” according to senior administration officials. The administration will also tell Tehran that inspectors must have full access to the key personnel who put together the clandestine plant and to the documents surrounding its construction, the officials said Saturday.

The demands, following the revelation Friday of the secret facility at a military base near the holy city of Qum, set the stage for the next chapter of a diplomatic drama that has toughened the West’s posture and heightened tensions with Iran. The first direct negotiations between the United States and Iran in 30 years are scheduled to open in Geneva on Thursday.

American and European officials say they will also press Iran to open what they suspect are nuclear-related sites to international inspectors, and to turn over notebooks and computers that they think may document efforts to design weapons.

President Obama has repeatedly said that Iran must show significant cooperation by the end of the year, establishing what officials say is effectively a three-month deadline. Interviews with American and European officials, however, suggest differences of opinion about how much time Iran should be given to show full compliance.