White House Chief of Staff John Kelly is expected to resign in the coming days—the latest shakeup to an administration in which frequent resignations and firings appear to be turning into the new normal. President Donald Trump is reportedly looking for Mr Kelly's replacement, according to CNN. A potential successor is Nick Ayers. He is currently serving as Vice President Mike Pence's chief of staff.

Mr Kelly, who is reportedly no longer in speaking terms with the president, is the second chief of staff to serve Mr Trump since his inauguration. Prior to Mr Kelly, former Republican National Committee Chairman Reince Priebus served the role.

Who is John Kelly?

A retired four-star Marine general, Mr Kelly served in the military for nearly five decades. He ran the military’s operations in Central America, South America and the Caribbean and has worked as a senior assistant to the Secretary of Defence. He also served tours of duty in Iraq and Afghanistan.

Mr Kelly will be the first current or former general to serve as White House Chief of Staff since Alexander Haig in the final stage of Richard Nixon’s administration in the 1970s.

Mr Kelly had been retired from the military for less than a year when Mr Trump asked him to run his Department of Homeland Security. In an 88-11 vote, the Senate confirmed Mr Kelly as Homeland Security Secretary in January, putting him in charge of the administration’s policies on issues including immigration, cyber-security, countering domestic terrorism and aviation security.

Where is he from?

Mr Kelly was born and raised in Boston and graduated from the University of Massachusetts. His son, Robert Michael Kelly, was killed in combat in Afghanistan in 2010.

What does Congress think of him?

Mr Kelly cruised through his Senate confirmation hearing in January, receiving praise from both Democrats and Republicans. During the proceeding, he also voiced opinions that appeared to differ from those expressed by Mr Trump, and demonstrated a notable degree of empathy for those who seek refuge in the US.

Iran's 'Trumpism' contest Show all 10 1 /10 Iran's 'Trumpism' contest Iran's 'Trumpism' contest A picture taken on July 3, 2017 shows a cartoon of US President Donald J. Trump and First Lady Melania Trump on display at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian woman looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian woman looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest Iranian cartoonist Hadi Asadi poses for a picture with a trophy and an award next to cartoons of US President Donald J. Trump, at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest Iranians look at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian woman looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest Iranian reformist cleric Mahmoud Doaei looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian man looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian woman looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest Iranian reformist cleric Mahmoud Doaei looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images

“They, for the most part, don’t want to come up and leave their homes, their families,” Mr Kelly said. “But there isn’t an awful lot of economic opportunity for them there.”

He has since taken a hard line against illegal immigration and vigorously backed the President on the need for a travel ban on refugees and immigrants from seven Muslim countries. The ban, which was allowed to go into limited effect by the Supreme Court in June, was later reduced to six countries.

The President and then Homeland Security Secretary listen to the national anthem in May (AP)

What do other people think of him?

Initially, several of Mr Trump’s advisers reportedly opposed the President’s choice to appoint Mr Kelly as his new chief of staff, suggesting the former general does not have the political savvy or background needed for the job.

Before becoming Homeland Secretary, Mr Kelly got some insight into how the government works when he served as a liaison to former Defence Secretary Leon Panetta. He also worked as a legislative assistant for the marine corps commandant in the mid 2000s.

Mr Kelly told CNN in June that “what I never saw on the military side was the level of the toxic kind of politics that are associated with what I do now,” repeating what he frequently tells members of Congress who criticise his actions: if you don’t like the laws, try to change them.

“John has also done a spectacular job at Homeland Security,” Mr Trump wrote on Twitter, calling Mr Kelly a “great American” and saying he had been a “true star of my Administration”.

However, Mr Kelly has not always appeared to be on the same page as Mr Trump, publicly questioning the need for a full border wall with Mexico and calling Russia a threat to the US as the President has tried to develop friendlier relations with Moscow.

Mr Kelly has also belittled the President's intelligence in past meetings, according to CNN. At one point, he was quoted calling Mr Trump an idiot and lamented about his job as chief of staff.

"He's an idiot. It's pointless to try to convince him of anything. He's gone off the rails. We're in crazytown," Kelly reportedly said. "I don't even know why any of us are here. This is the worst job I've ever had."