UNITED NATIONS/WASHINGTON (Reuters) - The chairman of the U.S. Senate Foreign Relations Committee said on Wednesday the U.N. Security Council’s refusal to respond to Iran’s ballistic missile tests defied Obama administration assurances that a ban on such tests would remain in place after the Iran nuclear deal. “As many of us feared, now it appears Iran can defy those restrictions with impunity fearing no pushback from the U.N. Security Council,” Republican Senator Bob Corker said, in response to a report by Reuters that diplomats suggested Iran’s tests do not technically violate provisions of Security Council Resolution 2231. Corker authored legislation giving the U.S. Congress the right to review the international nuclear deal announced in July and joined other members of his party in opposing it. Many U.S. lawmakers have demanded more sanctions over the missile tests. Council diplomats told Reuters on Wednesday experts from the 15-nation body would discuss Iran’s missile work on Friday. They are expected to consider the possibility of a council statement condemning the missile program, the diplomats said.  Iran’s recent ballistic tests involved missiles capable of delivering nuclear weapons and were “inconsistent with” and “in defiance of” council resolution 2231, adopted in July, the United States, Britain, France and Germany said in a joint letter to Spanish U.N. Ambassador Roman Oyarzun Marchesi and U.N. chief Ban Ki-moon. Spain has been assigned the task of coordinating council discussions on resolution 2231. The letter said missiles used in the recent launches were “inherently capable of delivering nuclear weapons.” It also asked that the Security Council discuss “appropriate responses” to Tehran’s failure to comply with its obligations and urged Ban to report back on Iranian missile work inconsistent with 2231. The letter stopped short of calling the Iranian launches a “violation” of the resolution, which “calls upon” Iran to refrain for up to eight years from activity, including launches, related to ballistic missiles designed with the capability of delivering nuclear weapons. Security Council diplomats have said the case for new U.N. sanctions was weak, hinging on interpretation of ambiguous language in a resolution adopted as part of a July nuclear deal to drastically restrict Iran’s nuclear work. Russia, a veto-wielding permanent member, has made clear it considers compliance with the appeal in resolution 2231 to be voluntary. Tehran has also said it is under no obligation to comply with the appeal to refrain from missile work and vowed to continue developing ballistic missiles. 