As tensions continue to run high on the Korean Peninsula, US ambassador to the United Nations Nikki Haley triggered a fierce backlash on Tuesday over a tweet about her spending the Fourth of July holiday in meetings after North Korea's latest test-launch of an intercontinental ballistic missile (ICBM).

US Secretary of State Rex Tillerson confirmed North Korea's launch of an ICBM on Tuesday saying it "represents a new escalation of the threat to the United States, our allies and partners, the region, and the world".

"Global action is required to stop a global threat," Tillerson said in a statement. "All countries should publicly demonstrate to North Korea that there are consequences to their pursuit of nuclear weapons."

He also confirmed that the US intends to bring North Korea's "provocative action" before the UN Security Council to "enact stronger measures to hold the DPRK accountable".

The same day, Haley tweeted: "Spending my 4th in meetings all day. #ThanksNorthKorea."

Her post immediately triggered furious criticism on Twitter, calling it an inappropriate tweet, given the gravity of the situation.

"Did you think being the United States ambassador to the United Nations was a 9-5 job with holidays off?" one person tweeted.

Many people criticised Haley for complaining about her job rather than thanking the US troops and first responders for their service on the 4th of July holiday. Others lambasted her saying: "What job did you think you were signing up for, exactly?"

American author Matthew Dicks tweeted: "Maybe find a new job? One that doesn't require you to work when enemy states gain long range nuclear capabilities".

"You're an ambassador now," one Twitter user wrote. "Stop tweeting like a teenage girl asked to do an extra shift at Starbucks."

"I noticed a lot of people in this administration talk and act like they're doing us a favour", one person wrote.