John Kelly and H.R. McMaster have chafed at Trump’s treatment of them in public and in private, which both at times have considered insulting, said sources.
Republicans in Congress last week launched an investigation into an Obama-era deal in which a Russian company bought a Canadian firm that owned some 20% of US uranium supplies.
White House officials believe John Kelly’s personal cellphone was compromised, raising concerns that hackers or foreign governments may have had access to data on the phone.
Steve Bannon was instrumental in some of Trump’s most contentious policy moves, including the immigration bans and abandoning the Paris climate accord.
A parade of business executives also broke ties with Trump on Wednesday, a day after he blamed white nationalists and counter-protesters in equal measure.
Trump’s loose decision-making style and open door policy has caused the White House to descend into chaos due to jockeying and infighting among staff and advisers.
Trump made the change a day after his new communications director, Anthony Scaramucci accused Priebus of being a leaker in a profanity-ridden interview.
The carnage was particularly embarrassing to Mexico as it came the same day US Department of Homeland Security secretary John Kelly was visiting the state.
The shootout took place near Las Varas, in the heart of one of Mexico’s drug trafficking regions, and involved two armed groups.
The hotly-debated program announced by President Obama, which would have let around 4 million undocumented people live in the US was ultimately rescinded after a protracted political tug of war.
The Trump administration is pressing Mexico to do more to stem the flow of migrants fleeing violence and poverty in the region in its ambitious plan for central America.
Only 1,125 children travelling with guardians, who are mostly women, were apprehended at the southern US border in March.
The ban will affect ten airports in eight countries in the Middle East and North Africa.
Several hundred asylum seekers, mainly from Africa but also the Middle East, have entered Canada and claimed that they were in the US legally.
Mexico opened legal aid centres at its 50 consulates across the US on Saturday to defend its citizens, the Mexican government said, amid worries of a crackdown on illegal immigration under US President Donald Trump.
The policy shift would allow the US government to keep parents in custody while they contest deportation or wait for asylum hearings.
In recent years, tens of thousands of Central American families including Guatemalans have moved to the US, many seeking asylum from ruthless street gangs.
Rights groups said that the raids were not business as usual and were more sweeping than operations conducted by the Obama administration.
The programme would no longer target groups such as white supremacists who have also carried out bombings and shootings in the US, sources said.
Romney, a fierce critic of Trump during the campaign, stopped short of an outright apology, saying he hoped Trump would lead the US to a better future.