WASHINGTON — The Obama administration moved on two fronts Monday to advance its nuclear diplomacy with Iran, with talks between top U.S. and Iranian diplomats and an aggressive effort to sell the emerging deal to skeptical American lawmakers and constituencies.

U.S. Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif met at the residence of Iran’s ambassador to the United Nations in New York for the first time since April 2, when world powers and Iran sealed a framework agreement that would limit Iran’s ability to build a nuclear weapon. They now have little more than two months to meet their own June 30 deadline for a comprehensive accord.

Earlier Kerry told a U.N. conference on nuclear non-proliferation that a deal would make the world a safer place. “I want you to know the hard work is far from over and some key issues remain unresolved,” he said. “But we are, in fact, closer than ever to the good comprehensive deal that we have been seeking. And if we can get there, the entire world will be safer.”

All the activity was taking place before the Senate begins debate Tuesday over empowering Congress to review and possibly reject any nuclear pact.