President Obama's National Security Advisor Susan Rice told Congressional investigators she 'unmasked' the identity of top Trump officials over an undisclosed meeting they had with the prince of the United Arab Emirates, CNN has learned.

Rice told members of the House Intelligence Committee last week that she requested names of Americans – usually blacked out in intelligence reports – to be revealed, after the UAE's crown prince Sheikh Mohammed bin Zayed al-Nahyan arrived in New York last December without notifying the US government.

The non-disclosure, which is customary, sparked interest in the meeting.

The crown prince had met with Trump officials including the president's ex-National Security Advisor Michael Flynn, his son-in-law Jared Kushner and another now-former White House official, Steve Bannon, sources told CNN.

The effort preceded the UAE trying to set up a backchannel between Russia and the incoming Trump administration.

President Obama's National Security Advisor Susan Rice told Congressional investigators that she 'unmasked' Trump officials during the transition because they met with a prince from the United Arab Emirates, who hadn't informed the US government of his travels

Susan Rice, photographed at the White House in 2013, was criticized by Republicans including President Trump and House Intelligence Committee Chairman Devin Nunes, R-Calif., for 'unmasking' Trump officials

Rice declined to comment to CNN about her testimony, while the crown prince's spokesperson also wouldn't speak on the record.

An individual described by CNN as a 'senior Middle East official' told the network's Manu Raju that the UAE did not 'mislead' the Obama administration about the crown prince's travel, though acknowledged that the US government was not notified in advance of the December 2016 trip.

The Trump Tower meeting, the official said, was simply about building a relationship with the incoming administration.

'The meeting was about ascertaining the Trump team's view of the region and sharing the UAE's view of the region and what the US role should be,' the official told CNN. 'No one was coming in to sell anything or arrange anything.'

Rice had previously been criticized for 'unmasking' Americans in the waning days of the Obama administration.

In April the president told the New York Times that Rice 'may have committed a crime by seeking to learn the identities of Trump associates swept up in surveillance of foreign officials by United States spy agencies.'

The House Intelligence Committee's chairman, Rep. Devin Nunes, R-Calif., made news when he showed up to warn the White House that Trump officials names were in the classified reports, meaning that someone had requested them to be 'unmasked.'

Now that Rice has delivered an explanation to Congress, members are walking their criticism back.

Rep. Trey Gowdy, R-S.C., an Intelligence Committee member told the Daily Caller that there was 'nothing that came up in her interview that led me to conclude' she had improperly unmasked the Trump officials or leaked their names to the press.

'I think what she did in her role was perfectly appropriate, so I think that people were impressed with her testimony,' said the committee's ranking Democrat, Rep. Adam Schiff, D-Calif.

As for Trump's accusations that Rice had broken the law, Schiff commented: 'It looks now like it did at the time, a baseless accusation and a slander against a dedicated public servant, not unlike the president's suggestion that he had been illegally wiretapped at Trump Tower,' the lawmaker said on CNN shortly after the UAE story broke.

Speaking to CNN, White House Press Secretary Sarah Huckabee Sanders didn't explicitly say whether Trump still thought Rice had committed a crime, instead focusing on whether unmasking and leaking needs to be probed.

'We've seen illegal leaking of classified materials, including the identifies of American citizens unmasked in intelligence reports,' she told the network. 'That's why the president called for Congress to investigate this matter and why the Department of Justice and Intelligence Community are doing all they can to stamp out this dangerous trend that undermines our national security.'

The December Trump Tower meeting, which took place in the transition period between the Obama and Trump administrations, happened before the UAE brokered a meeting to open lines of communication between Russia and the United States.

In April, the Washington Post reported that Blackwater's founder Erik Prince, a Trump ally, and a Russian close to Vladimir Putin, arranged by the UAE in the Seychelles Islands.

The effort was to create a back-channel line of communication between Moscow and President-elect Trump.

That meeting is now being investigated by Congress as they continue to look for links between the Trump campaign and Russia.