Iran must restore confidence in the "exclusively peaceful nature," of its nuclear program, US President Barack Obama and Russian President Dmitry Medvedev said in a joint statement issued prior to their meeting in London on Wednesday, stressing that they recognized that under the Non-Proliferation Treaty, Iran had the right to a civilian nuclear program. "We underline that Iran, as any other Non-Nuclear Weapons State-Party to the NPT, has assumed the obligation under Article II of that Treaty in relation to its non-nuclear weapon status," continued the statement, calling on Iran to "fully implement the relevant UN Security Council and the IAEA Board of Governors resolutions, including provision of required cooperation with the IAEA. " The two leaders reiterated their commitment to pursue a comprehensive diplomatic solution, including direct diplomacy and through negotiations conducted by the five permanent members of the UN Security Council plus Germany. The statement urged Iran to "seize this opportunity" to address the international community's concerns. In addition, the two jointly announced that they would try to put a new nuclear arms reduction deal in place before the existing treaty expires in December. They said the "era when our countries viewed each other as enemies is long over." They pledged to work together to limit the world's two largest nuclear arsenals, and the White House also announced that Obama was accepting Medvedev's invitation to visit Moscow this summer. As for nuclear arms control, the two said that "we are instructing our negotiators to start talks immediately on this new treaty and to report on results achieved in working out the new agreement by July." Their newly-professed commitment to reinvigorate arms-control initiatives that have lain dormant for years caused a stir at the London site of a G-20 summit that seemed otherwise transfixed on a deepening worldwide recession. Obama trumpeted the new arms undertaking as representing "great progress" between Moscow and Washington on areas where the two have mutual interests, although he also said he wouldn't try to minimize differences. "What we're seeing today is the beginning of new progress in US Russian relations," he said.