A Senate panel investigating alleged Russian interference in the US election has vowed a thorough inquiry.
The pledge comes as a similar inquiry in the House remains mired in acrimony.
The Senate hearing began on March 30. President Donald Trump’s son-in-law, Jared Kushner, is set to appear next week.
In the hearing’s opening remarks chairman Republican Richard Burr said “we are all targets of a sophisticated and capable adversary”.
Ranking Democrat Mark Warner said “Russia sought to hijack our democratic process” by employing a disinformation campaign on social media, which he describes as “Russian propaganda on steroids”.
Mark Warner said March 30 session would examine how Russia may have used technology to spread disinformation in the US, including the possible generation of fake news for voters in key states, such as Wisconsin, Michigan and Pennsylvania.
“We are in a whole new realm around cyber that provides opportunity for huge, huge threats to our basic democracy,” he said.
“You are seeing it right now.”
Former NSA director Keith Alexander will be one of those testifying on March 30.
Jared Kushner, who is married to President Trump’s daughter, Ivanka, volunteered to speak to the Senate Intelligence Committee, the White House has said, and is scheduled to appear next week.
Committee chairman Richard Burr said the panel would not shy away from the truth.
“This investigation’s scope will go wherever the intelligence leads,” he said.
When asked if he had seen any links between Donald Trump and Russian interference, he said: “We know that our challenge is to answer that question for the American people.”
Richard Burr said that there had been “conversations” about interviewing Michael Flynn – who was sacked by President Trump as national security adviser for misleading the vice-president over his contacts with the Russian ambassador – but his appearance is not confirmed.
The Trump presidency has been unable to shake off allegations that members of its team colluded with Russian officials during the election campaign. The president has regularly dismissed the claims as “fake news” and Russia has also ridiculed the allegations.
President Vladimir Putin did so again on March 30 at an Arctic forum, describing them as “nonsense”.
Richard Burr was a security adviser to the Trump campaign but insists he remains objective.
The House Intelligence Committee’s inquiry into the matter has been beset by partisan disputes.
Ranking Democrat Adam Schiff has insisted panel chairman Devin Nunes remove himself, after accusing him of colluding with the White House.
Last week, Devin Nunes went straight to the White House after hearing allegations about surveillance of Donald Trump’s team, rather than sharing them with Democrat colleagues on the panel.
Devin Nunes later apologized but insists he remains an objective chairman and will not step down.
As well as the two houses of Congress, the FBI is also conducting an investigation into the matter.
