Starting it off by firing missiles already…

The U.S. expects Iran will take months to live up to its end of a seven-nation nuclear pact that could eventually provide the country relief from international sanctions.

A milestone in the agreement was kicking in Sunday with Iran beginning to make major changes to an underground nuclear facility, a heavy water reactor and a site for enriching uranium. The changes will not happen immediately, and Iran must further constrain its nuclear program before relief from sanctions will occur.

Senior administration officials said Saturday they understand it’s in Iran’s best interest to work quickly, but they are only concerned that the work is done correctly. They insisted that no relief from the penalties will occur until the U.N.’s International Atomic Energy Agency has verified Iran’s compliance with the terms of the agreement. They said Iran’s work will almost certainly take more than the two months Iran has projected.

The administration officials spoke on a conference call with reporters, but under the condition that they not be identified by name.

As part of the nuclear agreement, President Barack Obama on Sunday planned to issue provisional waivers and a memorandum instructing U.S. agencies to lay the groundwork for relieving sanctions on Iran.

Iran has taken a series of provocative steps in recent weeks. Fighters from Iran have been working in concert with Russia in Syria, and a Revolutionary Court convicted a Washington Post reporter who has been held more than a year on charges including espionage. The court has not provided details on the verdict or sentence. Also, Iran successfully test-fired a guided long-range ballistic surface-to-surface missile.

But the U.S. officials asserted that those actions would be worse if they were backed up by a nation with a nuclear weapon. The officials emphasized that the seven-nation pact is focused solely on resolving the nuclear issue.