Sen. Lindsey Graham says U.S. intelligence agencies tell him that a conversation he had with a foreign individual was picked up in surveillance and that an unknown U.S. official or officials asked to know his identity as a party in the conversation.

Graham says he doesn't know if intelligence agencies actually revealed his name. But he's sent a letter to the FBI, CIA and the National Security Agency seeking information on any incidental collection of his communications with foreign targets.

Graham says he wants to know if Obama administration officials sought the unmasking of Americans in foreign intelligence reports for political reasons.

Graham, R-S.C., spoke Friday on Fox News Channel's "America's Newsroom."

The Senate intelligence committee has invited top spy and law enforcement officials to testify Wednesday at a hearing about the federal law governing foreign intelligence collection.

The hearing is being held because the Foreign Intelligence Surveillance Act is expiring at the end of the year. But lawmakers are expected also to ask questions about the committee's investigation into Russian activities during the presidential election.

Democrats will likely ask in either the open or closed session about reports that President Donald Trump wanted Director of National Intelligence Dan Coats and National Security Agency Director Adm. Mike Rogers to say publicly that there was no collusion between the Russians and the Trump campaign.

Acting FBI Director Andrew McCabe and deputy Attorney General Rod Rosenstein also are expected to testify.

House Democratic Leader Nancy Pelosi is objecting to subpoenas issued by the intelligence committee's Republican chairman on the Russia probe.

Pelosi says Rep. Devin Nunes should not be issuing subpoenas because he stepped aside from the investigation after being criticized for being too close to the White House. She says she shared her objection with House Speaker Paul Ryan.

Nunes sent subpoenas to the CIA, FBI and National Security Agency. They seek information about Obama administration requests to unmask the identities of Americans named in foreign intelligence reports. Republicans say Nunes is still chairman and still responsible for making sure the identities of Americans are not unmasked for political purposes.

President Vladimir Putin is ridiculing allegations of Russian meddling in U.S. elections, accusing the Democrats of trying to shift blame for their defeat and likening the accusations against Russia to anti-Semitism.

During a panel discussion at St. Petersburg's economic forum, Putin said the claims of Russian interference in the U.S. election contained "nothing concrete, only assumptions."

Asked about the "fingerprints" -- IP addresses allegedly belonging to Russian hackers -- he said those could have been easily rigged and couldn't stand as credible evidence.

Putin said sarcastically: "What fingerprints? Hoof prints? Horn prints? Technology experts can invent anything and put the blame on anyone."