The Wall Street Journal reports: Talks over Iran’s nuclear program have hit a stumbling block a week before a key deadline because Tehran has failed to cooperate with a United Nations probe into whether it tried to build atomic weapons in the past, say people close to the negotiations.

In response, these people say, the U.S. and its diplomatic partners are revising their demands on Iran to address these concerns before they agree to finalize a nuclear deal, which would repeal U.N. sanctions against the country.

“Progress has been very limited,” Yukiya Amano, who heads the U.N.’s International Atomic Energy Agency, told The Wall Street Journal this week. “No more new issues” have been addressed. [Continue reading…]