Jeff Zucker, the president of CNN and a frequent target of President Donald Trump, has announced he will be going on medical leave.

'Jeff Zucker just ended the CNN morning meeting with news of his own: He will be taking a six week leave for elective surgery to address a heart condition he has had for 10 years,' wrote Reliable Sources host Brian Stelter on Twitter.

'He assured everyone he is going to be just fine. All of us are wishing him a very speedy recovery.'

Zucker, 53, became president of CNN Worldwide back in 2013, and was previously president and CEO of NBC Universal.

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Leave of absence: Jeff Zucker (above with Preisdent Trump and Melania in 2007) told employees at a CNN meeting on Thursday that he would be taking a medical leave for a heart condition he has had for 10 years

Praise: Zucker, 53, and Trump were on good terms for years, and the real estate scion even endorsed Zucker for the job at CNN in 2012 (above)

Panned: Their relationship began to sour over the primary, and President Trump now calls CNN 'fake news' and Zucker 'Little Jeff Z' (above)

President Trump and Zucker have a relationship that stretches back more than a decade, to the time when both men were working for NBC.

That relationship was positive for years, but has been acrimonious at best for the past two years.

Zucker is frequently mentioned by President Trump on Twitter, who has taken to calling him 'Little Jeff Z.'

Zucker is approximately six inches shorter than President Trump, who claims to be 6ft 2in.

President Trump went after Zucker just this past weekend, writing: 'Remember, it was Little Jeff Z and his people, who are told exactly what to say, who said I could not win the election in that “there was no way to 270” (over & over again) in the Electoral College. I got 306! They were sooooo wrong in their election coverage. Still hurting!'

The two had still been close throughout the primary, at least according to one source.

Morning Joe host Joe Scarborough appeared on Politico's Off Message podcast back in 2016 and revealed: 'Trump laughs and calls Zucker "my personal booker," because Zucker will call Trump [to appear on the network].'

Zucker was previously CEO of BC/Universal

Scarborough continued: 'He hasn't said that publicly.But he's said it. I've said it publicly now. But, you know, Trump will laugh every time Zucker calls because Zucker will call to personally book him.'

Zucker was head of NBC when the network acquired The Apprentice, and Trump had for a time been very fond of him, writing on Twitter back in 2012; 'Great move by CNN if they sign Jeff Zucker. He was responsible for me and The Apprentice on NBC - became #1 show!'

That all changed however during the course of the primary.

Zucker and CNN began to come under fire from members of both political parttes for the amount of coverage it gave Trump, and the decision at times to air entire rallies.

At the same time, Trump and his supporters started to grow irate at how nbegative much of that coverage was on the network.

Then, in his first and only press conference during the transition, President Trump went after Jim Acosta, CNN's Chief White House Correspondent, calling him and the network 'fake news.'

That comment set the tone for how Acosta, Zucker and the network have been treated by President Trump and many in his administration since the real estate scion was sworn into office.