Obama and Medvedev caught in unguarded missile remarks
TV cameras have recorded US President Barack Obama making unguarded comments with Russian President Dmitry Medvedev.
Mr Obama said he would have more "flexibility" on difficult issues such as the US missile defence plans after November's election.
Mr Medvedev said he would relay the message to Vladimir, a reference to newly elected President Vladimir Putin.
The White House later released a statement playing down the importance of the remarks.
"Since 2012 is an election year in both countries, with an election and leadership transition in Russia and an election in the United States, it is clearly not a year in which we are going to achieve a breakthrough," said deputy national security adviser Ben Rhodes.
Moscow has long opposed American plans to build a so-called defence shield in and around Europe capable of shooting down ballistic missiles.
Mr Obama and Mr Medvedev met during a nuclear summit in the South Korean capital Seoul.
According to a transcript of the recorded remarks carried by ABC News, Mr Obama told his Russian counterpart: "On all these issues, but particularly missile defence, this, this can be solved but it's important for him to give me space."
Mr Medvedev responded: "Yeah, I understand. I understand your message about space. Space for you."
Mr Obama then said: "This is my last election. After my election I have more flexibility."
Mr Medvedev replied: "I understand. I will transmit this information to Vladimir."
Numerous politicians have found remarks that they thought were private being captured by open microphones.
In 2006 US President George Bush was caught in a candid conversation with British Prime Minister Tony Blair. It became famous for Mr Bush starting the exchange with "Yo, Blair".
And in November last year President Sarkozy was heard describing the Israeli prime minister Benjamin Netanyahu as a "liar", also while talking with Mr Obama.