President Obama has told French President Francois Hollande that the US is not spying on his phone calls.
The two leaders spoke by phone earlier after the release of WikiLeaks documents which claimed the National Security Agency had spied on Hollande and his two predecessors, Nicolas Sarkozy and Jacques Chirac.
The White House said Mr Obama had "reiterated that we have abided by the commitment we made to our French counterparts in late 2013 that we are not targeting and will not target the communications of the French president".
Mr Hollande had earlier described the allegations as "unacceptable between allies".
Francois Hollande, the French president, has branded as "unacceptable" the reported spying by the US on three French presidents.
The allegations that the National Security Agency spied on Hollande, and before him presidents Jacques Chirac and Nicolas Sarkozy, were made by Wikileaks, which cited intelligence reports.
"France will not tolerate actions that threaten its security and the protection of its interests," Hollande's office said in a statement.
"Commitments were made by the US authorities. They need to be recalled and strictly respected."
The US ambassador to Paris was summoned to the French foreign ministry on Wednesday over the claims.
Prosecutors from Sweden have submitted a formal request to WikiLeaks founder Julian Assange, asking his permission to question him in London where he has claimed asylum in the Ecuadorian embassy.
The prosecutor wants to quiz him and carry out DNA tests in connection with allegations of sexual assault and rape, which Assange denies.
The Australian has been hiding inside the South American country's UK embassy for almost three years, in fear of being extradited to Sweden.
He says he believes if he was sent to Sweden, he would then be extradited to the United States where he faces being tried for one of the biggest information leaks in the country's history through his website.
Assange's Swedish lawyer has reportedly welcomed the request to question him, but said he is concerned that the process could take some time, as both Britain and Ecuador will have to give their permission for the interview to take place.
Assange has previously offered to be interviewed inside the embassy, but Swedish authorities had refused until now.
We welcome and see it also as a big victory ... for Julian Assange, that what we have demanded is finally going to happen.
WikLeaks founder Julian Assange announced he will be leaving the Ecuadorian embassy "soon" after two years at the building.
Assange told a press conference, "I am leaving the embassy soon - but perhaps not for the reasons that the Murdoch press and Sky News are saying at the moment".
By Juliet Bremner: UK Editor
There is a huge number of media outside, but a police officer has just been out to relay a message that there will be no further events or movement here at the Ecuadorian embassy today.
I suspect this is a big publicity stunt to try and get the British Government to engage in a discussion about his release.
Julian Assange has hinted at unspecified health "difficulties" - mentioning in particular the lack of outdoor space and sunlight at the Ecuadorean Embassy in London where he has been holed up for two years.
In relation to my health, as you can imagine ... being detained in this country in various ways for four years, and then in this embassy for two years ... It is an environment in which any healthy person would find themselves soon enough with various difficulties.
Julian Assange has stressed he has not been charged with an offence in the UK or in Sweden "at any time".
"The basis under which my asylum was granted here [at the Ecuadorian embassy] is the ongoing US investigation into me and WikiLeaks", he said during a press conference.
"I am leaving the embassy soon, but perhaps not for the reasons that the ... press are saying at the moment," Julian Assange has told reporters.
Julian Assange says: "It is often falsely reported that women in Sweden have accused me of the serious crime of rape. That is false. No woman has done so."
WikiLeaks founder Julian Assange has said the position Ecuador has taken on his case "is the correct one".
Assange sought refuge inside Ecuador's London embassy two years ago in a bid to avoid extradition to Sweden for questioning over sexual misconduct allegations.
He has denied the claims made against him.