and jean michel cousteau on the long-term impact of the oil spill. but first the other news of the day. here's kwame holman in our news room. >> holman: iranian president mahmoud ahmadinejad urged the international community to support his country's agreement brokered with turkey and brazil to swap nuclear fuel. he said it would resolve the nuclear issue. but he warned it is a one-time opportunities, and that imposing more sanctions on iran would be a mistake. the u.n. security council is scheduled to vote on a new round of sanctions tomorrow morning. in washington, a state department spokesman said iran has had more than enough time to change its course. >> iran wants to portray itself as the victim here. iran is not the victim. iran is an actor in this play. it's iran that has failed to come forward and meet its international obligations. what we are saying is that failure has consequences. we are not closing the door to any step beyond, you know, the sanctions vote tomorrow. >> holman: in london u.s. defense secretary robert gates insisted it's no

. >> on the oil spill, underwater footage from explorer jean-michel cousteau. we talked to him about his team's dives into the gulf last week. all that and much more is on our web sites. >> ifill: and that's the newshour for tonight. i'm gwen ifill. >> lehrer: and i'm jim lehrer. we'll see you online and again here tomorrow evening. thank you, and good night. major funding for the pbs newshour has been provided by: >> this is the engine that connects zero emission technologies to breathing a little easier, while taking 4.6 million truckloads off the road every year. bnsf, the engine that connects us. the national science foundation. supporting education and research across all fields of science and engineering. and with the ongoing support of these institutions and foundations. and... this program was made possible by the corporation for public broadcasting. and by contributions to your pbs station from viewers like you. thank you. captioning sponsored by macneil/lehrer productions captioned by media access group at wgbh access.wgbh.org