The US president says his decision to shelve a missile defence plan was not dictated by Russian opposition.
"The Russians don't make determinations about what our defence posture is," Barack Obama told CBS television.
"If the by-product of it is that the Russians feel a little less paranoid... then that's a bonus," Mr Obama said.
US conservatives have criticised the decision to scrap the plan to deploy interceptor missiles in Poland and a radar station in the Czech Republic.
Mr Obama's predecessor, George W Bush, had argued that the system was necessary to deal with potential threats from Iran.
MARDELL'S AMERICA
Mark Mardell
The message is that Obama is still keeping his cool, and sticking to long-term goals
Mark Mardell
BBC North America editor
Mardell assesses Obama interviews
Moscow said it was aimed against Russia, and has welcomed the US decision to abandon it.
Mr Obama's plan is to replace it with a defence system using sea and land-based interceptors.
In a series of wide-ranging interviews with US television networks on Sunday, Mr Obama also focused on:
• The economy: "I want to be clear, that probably the jobs picture is not going to improve considerably and it could even get a little bit worse over the next couple of months." - CNN's State of the Union.
• Healthcare: "About two-thirds of what we've proposed would be from money that's already in the healthcare system but just being spent badly. And as I said before, this is not me making wild assertions." - CBS's Face the Nation. read more
