(CNN) -- President Donald Trump said Tuesday that he has asked national security adviser John Bolton to resign, noting that he "strongly disagreed with many of his suggestions as did others in the administration."
"I informed John Bolton last night that his services are no longer needed at the White House. I disagreed strongly with many of his suggestions, as did others in the Administration, and therefore I asked John for his resignation, which was given to me this morning," Trump tweeted. "I thank John very much for his service. I will be naming a new National Security Advisor next week," he added.
The tweet came just one hour after the White House press office said Bolton was scheduled to appear at a Tuesday press briefing alongside Secretary of State Mike Pompeo and Treasury Secretary Steve Mnuchin.
Bolton tweeted minutes after Trump's announcement, "I offered to resign last night and President Trump said, 'Let's talk about it tomorrow.'"
Trump was irked by reports that he had faced internal pushback from Bolton over his decision to host leaders of the Taliban at Camp David, multiple people familiar with his frustration say. The President announced the plans for the meeting were canceled on Saturday.
CNN reported last week that tensions between top figures on Trump's national security team had devolved into all-out hostility, creating a deep disconnect between staffers on the National Security Council, led by Bolton, and the rest of the administration, six people familiar with the matter said.
Bolton was initially brought into the administration last year to replace HR McMaster partly due to his hawkish position on Iran -- supporting Trump's exit from the Iran nuclear deal -- but he soon began to clash with the President's vision for diplomacy in North Korea and most recently on Afghanistan.
The campaign by Trump allies to push Bolton out of the administration had ramped up in recent weeks, multiple sources told CNN.
The President had received multiple phone calls and appeals to replace Bolton with someone who agreed with him more and was willing to follow through with his decisions when he didn't. This was something Trump heard since he hired Bolton — but people noticed the President's frustration with him was growing in recent weeks so they upped the pressure.
A senior administration official echoed that sentiment, telling CNN that Trump has been getting more and more irritated with Bolton over the past several months for his statements on Iran, Venezuela and now Afghanistan.
Trump no longer believed Bolton could advocate for the President's agenda, and instead felt he was harming his credibility, the official said.
Trump also felt like Bolton wasn't a forceful enough advocate for him in the media -- and that when he did make appearances, he wasn't convincing enough, since it was evident he didn't believe in some of Trump's foreign policy goals, the source added.
Another senior administration official told CNN that White House and national security officials learned about Bolton's firing from Trump's tweet. The official described aides as frantically trying to figure things out following the tweet.
Utah Republican Sen. Mitt Romney called his departure a "huge loss" for the Trump administration and said he was "very unhappy" to learn Bolton was leaving.
"The loss of John Bolton as a senior leader in foreign policy is an extraordinary loss for our nation and for the White House," Romney told reporters, adding that he was an important voice in the room because he would take a different view.
But fellow Republican Sen. Rand Paul of Kentucky, a leading Bolton critic, told CNN that "the chances of war worldwide go greatly down" with his firing.
"He has a naive view that believes we should recreate the world in our own image by toppling countries by violent overthrow and somehow democracy will prevail," Paul said about Bolton.