The Wall Street Journal reports: Iran agreed to host a high-level team of United Nation’s nuclear inspectors later this month, Western diplomats said, a surprise development that could help to curb building tensions with the West.

The diplomats on Thursday said Iran had tentatively agreed to receive a delegation from the United Nation’s International Atomic Energy Agency headed by the agency’s chief weapons inspector, Herman Nackaerts. The diplomats, who are based in Vienna, said the visit was tentatively set for Jan. 28.

Unclear, said the diplomats, was whether Tehran would let the inspectors visit key nuclear sites and interview the Iranian official the U.S. and the U.N. agency believe may head a nuclear-weapons program.