Trump interacts with reporters as he welcomes Vietnam's Nguyen in the Oval Office at the White House in Washington Thomson Reuters WASHINGTON (Reuters) - Wading into a political feud over the latest subpoenas in the U.S. House Intelligence Committee's Russia probe, U.S. President Donald Trump on Thursday backed efforts to investigate actions by U.S. security and other officials under previous President Barack Obama.

"The big story is the 'unmasking and surveillance' of people that took place during the Obama Administration," Trump said in a tweet, one day after the committee's Republican chairman subpoenaed the CIA, FBI and National Security Agency amid charges by Democrats that they were not consulted.

(Writing by Susan Heavey; Editing by Chizu Nomiyama)