US President Donald Trump has boasted that his nuclear button is "much bigger" and "more powerful" than North Korean leader Kim Jong-un's.
Mr Trump's tweet is the latest contribution to the bickering, increasingly personalised feud between the nuclear-armed leaders.
Mr Kim threatened earlier this week that his nuclear launch button was "always on my table".
Unsurprisingly, Mr Trump's unorthodox words sent social media into a frenzy.
It ended a quick-fire day of tweeting that included taking credit for a lack of airplane crashes, announcing awards for "corrupt media", and threatening to pull aid from Palestinians who do not show "appreciation or respect".
Mr Trump's latest comment states the obvious: any US president has immediate access to the nuclear codes and the US has the world's biggest nuclear arsenal.
North Korea claims it has nuclear weapons and could attack the US, but while analysts agree that Pyongyang has nuclear weapons, it is not clear whether it has the technology use them in anger.
Just as the president's unorthodox Twitter habits have puzzled observers in the past, the tweet is again redefining what's considered diplomacy or presidential tone.
Many people online have expressed alarm at the apparently light-hearted use of nuclear threats by world leaders.
But Mr Trump's supporters have defended him, saying his comments are both factually accurate and show American strength and resolve.
However, much of the social media comment has focused on Mr Trump's apparent fixation with size.
During his presidential campaign, he had a long-running spat with Marco Rubio over the size of his hands.
At the time, Mr Trump insisted: "He referred to my hands - 'if they are small, something else must be small'. I guarantee you there is no problem. I guarantee".
This connection was not missed by social media users.
So far, the only button on Mr Trump's desk the world knew about was one that orders a Diet Coke to be brought to his room.
At least that's what several US media reported after seeing said button in action during interviews.
Earlier this year, the North Korean denounced the US president as a "dotard", while Mr Trump has developed the nickname of Little Rocket Man for Mr Kim.
Beyond threatening the US, Mr Kim's New Year's Day speech also took many people by surprise when he said he was "open to dialogue" with the South, and would like to send a delegation to the Winter Olympics, taking place in South Korea next month.
South Korean President Moon said he saw the Olympics as a "groundbreaking chance" to improve relations.
Seoul offered to attend high-level talks with North Korea next week to discuss its possible participation.
It would be the first bilateral meeting in more than two years between the two Koreas.
On Wednesday, Seoul said North Korea would restore the inter-Korean hotline, thus opening a channel for dialogue leading to a potential meeting.
Mr Trump also used his Tuesday evening tweets to threaten to cut off aid to Palestinians, saying the US received "no appreciation or respect" in return for its aid.
Earlier, he made similar comments about Pakistan, saying the US had received only "lies and deceit" in exchange for billions of dollars in aid.