The United States' so-called 'nuclear football' briefcase was spotted being carried out of Downing Street after President Joe Biden visited UK Prime Minister Rishi Sunak today.
The ominous black leather suitcase is carried with the President whenever he is away from the White House and its appearance sends a strong message to warmongering Russian President Vladimir Putin.
It contains everything needed so the Commander-In-Chief can authorise the deployment of nuclear weapons if needed, despite being away from command centres - including nuclear authorisation codes.
It has also been known as the atomic football and the President's Emergency Satchel, among other names, and is carried with care by a military aide and member of the armed forces, following closely behind Mr Biden.
Biden and Sunak met during the President's short layover in London ahead of a crunch NATO summit in Vilnius, Lithuania, which is likely to see wrangling between allies over Ukraine's path to membership of the alliance.
And Russia's continued threats to use nuclear weapons in Ukraine loom large over the vital summit. While NATO officials think he's bluffing, it is quite possible that Putin will resume his nuclear saber-rattling again as world leaders gather in Vilnius.
Belarusian President Alexander Lukashenko also said last month that his country has received Russian tactical nuclear weapons, warning that he would order their use to protect his country.
And in June, Putin told the West to "go to hell" as he boasted about having "more nuclear missiles than NATO countries".
In October, Biden had made a sobering warning about nuclear "Armageddon" as he said Putin was "not joking" about using nukes.
"For the first time since the Cuban Missile Crisis, we have a direct threat to the use of nuclear weapons, if in fact things continue down the path they'd been going," Biden told Democratic donors in New York.
He also said, "we have not faced the prospect of Armageddon since Kennedy and the Cuban missile crisis."
In the 1962 Cuban Missile Crisis, the United States under President John Kennedy and Soviet Union under its leader, Nikita Khrushchev, came close to the use of nuclear weapons over the presence of Soviet missiles in Cuba.
Putin, said Biden in October, is "not joking when he talks about potential use of tactical nuclear weapons or biological or chemical weapons, because his military is, you might say, is significantly underperforming."
At the St Petersburg Economic Forum in June, Putin confirmed he had moved nuclear weapons to within striking distance of NATO countries but claimed the nukes were only a "precautionary measure" against Ukraine and those aiding the neighbouring country invaded by Russia.
A battery of tactical nuclear weapons have been stationed to Belarus, marking the first time Russia has moved weapons outside of the country since the fall of the Soviet Union.
The Russian president told the forum that the lethal munitions would only be used if Russia's territory or state was under threat.
He said the move was about "containment" and to remind any of his adversaries who may be "thinking of inflicting a strategic defeat on us".
When asked if he would consider using the weapons, he replied: "Why should we threaten the whole world? I have already said that the use of extreme measures is possible in case there is a danger to Russian statehood."
Putin went on: “Nuclear weapons are created to ensure our security in the broadest sense of the word and the existence of the Russian state. But we, firstly, do not have such a need.
"Extreme means may be used if there is a threat to Russia’s statehood. In this case, we will certainly use all the forces and means that the Russian state has at its disposal.”
He added: "Just talking about this lowers the nuclear threshold. We have more than NATO countries and they want to reduce our numbers. Go to hell."