President Donald Trump and German Chancellor Angela Merkel at a joint news conference on March 17. Pablo Martinez Monsivais/AP President Donald Trump, confronted about his explosive claim that he had been wiretapped by his predecessor, told German Chancellor Angela Merkel during a Friday news conference, "At least we have something in common, perhaps."

The jab was a reference to reports in 2013 that said the National Security Agency, under President Barack Obama, had been intercepting Merkel's phone calls and spying on German officials. Der Spiegel reported at the time that the NSA had been using the US embassy in Berlin as a listening station.

Merkel called Obama in October 2013 and demanded he explain the reports, and Germany launched an investigation into the matter. The White House denied that Merkel had ever been a surveillance target, and the probe was ultimately dropped. But many experts later said that it was fairly standard practice for friendly nations to spy on one another.

Trump made the comment as the White House faced a new wave of backlash related to Trump's allegations against Obama. On Thursday, White House press secretary Sean Spicer read from unverified reports that said a British intelligence agency, the Government Communications Headquarters, or GCHQ, conspired with Obama to wiretap Trump before the election.

The accusation was first leveled by Andrew Napolitano, a former judge, on Fox News.

Spicer's comment prompted a near-immediate reaction from GCHQ, which released a rare public statement categorically denying any involvement and calling the accusation "utterly ridiculous."

"Recent allegations made by media commentator Judge Andrew Napolitano about GCHQ being asked to conduct 'wiretapping' against the then president-elect are nonsense," the statement read. "They are utterly ridiculous and should be ignored."

When asked on Friday if the White House regretted accusing the UK of helping Obama wiretap Trump Tower, Trump said that "all we did was quote" a Fox commentator, so "you should be talking to Fox."

Fox released a statement on Friday saying that Napolitano stood by his reporting, but Fox News host Shep Smith later said, "Fox News cannot confirm Judge Napolitano's commentary.

"Fox News knows of no evidence of any kind that the now president of the United States was surveilled at any time, any way. Full stop," Smith said.

Watch the exchange between Merkel and Trump: