The chances of reviving the 2015 Iran nuclear deal are shaky at best and Washington is ready to tighten sanctions on Tehran and respond to "any Iranian escalation" with Israel and other allies if the pact cannot be saved, the United States' Iran envoy said on Wednesday.
"We do not have a deal with Iran, and prospects for reaching one are, at best, tenuous," U.S. Special Envoy for Iran Rob Malley said in prepared congressional testimony, alluding to indirect U.S.-Iran talks in Vienna that unraveled in March.
