WASHINGTON (AFP) - Edward Snowden may have acted in concert with a foreign power in exposing United States (US) surveillance programs, two Republican lawmakers suggested on Sunday.

"I think there are some interesting questions we have to answer that certainly would lend one to believe that the Russians had at least in some part something to do" with the affair, House Intelligence Committee chairman Mike Rogers told CBS's Face The Nation.

Mr Rogers, a Republican, said "everything from how he prepared to leave, his route of departure and how he quickly ended up in Moscow" put Snowden's ties at question.

The "vast majority" of the information leaked by Snowden, Mr Rogers said "had nothing to do with the National Security Agency (NSA) programme and everything to do with our military capabilities, army, navy, air force, marines." Mr Rogers, appearing in a second interview on NBC's Meet The Press, said he didn't think "it was a gee-whiz luck event that he ended up in Moscow under the handling of the FSB" state security agency in Russia.

Mr Michael McCaul, chairman of the House Homeland Security Committee, told ABC's This Week that he didn't believe "Mr Snowden was capable of doing everything himself.

"I believe he was helped by others," the congressman said in an interview from Moscow.

Mr McCaul, a Republican, said he could not say "definitively" that Russia was involved, "but I believe he was cultivated".

US President Barack Obama curtailed the reach of massive US National Security Agency phone surveillance sweeps on Friday, in a long-awaited speech designed to quell a furor over the programs exposed by Snowden.

The president, however, also said bulk data collection must go on to protect America from terrorists.