The story

President Obama said Tuesday that reports of a U.S. offer to kill a proposed missile defense system in exchange for Russian assistance in preventing Iran's acquisition of nuclear weapons were inaccurate.

Obama acknowledged he had sent Russian President Dmitry Medvedev a "very lengthy letter talking about a whole range of issues," including nuclear proliferation and terrorism, but said there was no quid pro quo regarding the proposed defense system in Eastern Europe.

"What I said in the letter was that, obviously, to the extent that we are lessening Iran's commitment to nuclear weapons, then that reduces the pressure for -- or the need for -- a missile defense system," Obama said. Read full article »

CNN's Matthew Chance, Jill Dougherty, Suzanne Malveaux, Mike Mount and Alan Silverleib contributed to this report.

All About Iran • Dmitry Medvedev • Barack Obama