A look at John Bolton's tenure in Trump administration

John Bolton's tenure as President Donald Trump's national security adviser included disagreements on several key policy issues, including relations with Iran and North Korea.

During his year and a half at the White House, Bolton had particular success in shaping the administration's policies toward the United Nations and other international organizations, such as the International Criminal Court, as well as advocating for hardline measures on Venezuela and Cuba.

Bolton had launched a broadside campaign against the ICC that resulted in the U.S. revoking the visa of the court's chief prosecutor after she sought permission to open an investigation into alleged war crimes committed by American troops and others in Afghanistan.

Here are other highlights of the Bolton tenure:

— March 22, 2018: Trump announces he will appoint former U.N. Ambassador John Bolton as national security adviser, the third person to hold the position in just over a year. Bolton replaces H.R. McMaster, who was brought in after Trump's first national security adviser, Michael Flynn, was dismissed after less than a month in office.

— May 8, 2018: Trump announces withdrawal from the 2015 Iranian nuclear deal, a position advocated by Bolton. The deal had been negotiated by the Obama administration to limit Iran's nuclear program in exchange for easing sanctions, and some in the administration favored staying in the agreement.

— Nov. 15, 2018: Bolton ally and deputy national security adviser Mira Ricardel is forced out after first lady Melania Trump's office issued a public statement calling for her ouster.

— Jan. 9, 2019: President Recep Tayyip Erdogan of Turkey refuses to meet with Bolton during his visit to Turkey to discuss U.S. plans to withdraw troops from Syria. The Turkish president was angered after Bolton called for Turkish security assurances for the U.S.-backed Kurdish forces as a condition for the withdrawal.

— May 26, 2019: Trump seems to undercut Bolton's public condemnation of missile tests by North Korea. "North Korea fired off some small weapons, which disturbed some of my people, and others, but not me," Trump tweeted. "Some" of his "people" appeared to include Bolton, who had told reporters just hours earlier that North Korean missile tests violated U.N. Security Council resolutions.

— June 21, 2019: Trump says he authorized but then called off a military strike against Iran in retaliation for Iran's downing of an American drone aircraft. Bolton had supported carrying out the U.S. attack.

— June 30, 2019: Bolton visits Mongolia while Trump goes to the Korean Demilitarized Zone for a historic handshake with North Korean leader Kim Jong Un, suggesting a growing divide between Bolton and Trump.

— Sept. 7, 2019: Trump cancels what he calls a secret meeting at Camp David with Taliban and Afghan leaders, following a Taliban bombing in Kabul that killed 12 people, including one American soldier. Trump defends the idea of bringing the Taliban to the presidential retreat in search of peace, a move that Bolton had argued against.

— Sept. 10, 2019: Bolton submits his resignation after it was requested by Trump. The two men offer opposing accounts on the departure.