U.S. Vice President Mike Pence has hired a lawyer known for defending government officials in high-profile investigations to help him with probes into whether there were ties between the election campaign of U.S. President Donald Trump and Russia, his office said on Thursday.

U.S. intelligence agencies have concluded that Moscow interfered in last year's presidential campaign to try to tilt the vote in Trump's favor.

Trump, who hired his own lawyer last month for probes by a special counsel and congressional committees, lashed out on Thursday after a report that he was under investigation for possible obstruction of justice.