North Korea conducted a series of recent missile tests and its sixth nuclear test in early September, which has put the U.S. on high alert.
She is the third Trump official to be reprimanded for similar ethics breaches.
This is not the first time that Trump has sought to demean someone with the prefix "little."
"The time for well-meaning, diplomatic words in this Council has passed," Nikki Haley told the U.N. Security Council.
A new report found that U.S. intelligence was surveilling the area where the plane crashed, killing U.N. chief Dag Hammarskjöld in 1961.
The regime has already said it considers shooting U.S. jets outside of its airspace justified.
North Korea's Foreign Minister Ri Yong Ho said President Donald Trump's latest Twitter attack on Kim Jong Un amounted to a declaration of war.
Did the U.S. military just get attacked with fake news in East Asia?
The White House said Gorka's claim was "100 percent false and Sebastian Gorka and Steve Bannon played no role in the U.N. speech."
Russia did not appreciate President Donald Trump's vow to "totally destroy" North Korea, and has plans of its own to solve the nuclear crisis.
Trump sat down for lunch with other world leaders and U.N. representatives after discussing military action against North Korea.
It was perhaps the most awkward moment of the president's speech.
During the president's first address to the U.N., he asked that the organization work more effectively.
North Korea's delegation to the United Nations was in no mood to listen to President Donald Trump.
Officials have indicated Trump will address the threats posed by North Korea and Iran in his first speech to the organization.
The Rohingya crisis led more thousands march on the Myanmar embassy in Bangladesh on Monday — but there's no end in sight for what a U.N. official has called "ethnic cleansing."
After turning down the invite and sending Russia's foreign minister instead, the Kremlin unveiled Putin's alternative plans.