The Biden administration believes that everyone is stupid enough to eat the bullshit it produces.
Consider this latest nonsense:
The United States on Wednesday accused North Korea of covertly shipping a “significant number” of artillery shells to Russia to aid its war effort in Ukraine, a sign that Moscow is increasingly turning to pariah states for military supplies as the grinding conflict persists.
The White House’s national security spokesman, John Kirby, said that it was unclear if the artillery munitions, which are being transferred through the Middle East and North Africa, had reached Russia. The United States does not believe that the additional weapons will alter the trajectory of the war.
“Our indications are the DPRK is covertly supplying and we’re going to monitor to see whether shipments are received,” Mr. Kirby told reporters on Wednesday, referring to the Democratic People’s Republic of Korea. “Our information indicates that they’re trying to obscure the method of supply by funneling them through other countries in the Middle East and North Africa.”
Russia and North Korea have a common border. Artillery ammunition is heavy and one needs lots of it. That is why it is preferable to transport it in bulk – by ship or railway.
Russia's and North Korea's railways are connected.

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In 2019 Kim Jong Un visited Russia by train. While the passenger traffic had been closed down due to Covid quarantine measures it has recently been reopened. The U.S. has no means to know what products are in the boxcars and containers that travel across that border.
There are also ships. In 2017 the U.S. accused North Korea of exporting coal via Russia to third parties:
[T]he secretive Communist state has at least three times since then shipped coal to the Russian ports of Nakhodka and Kholmsk, where it was unloaded at docks and reloaded onto ships that took it to South Korea or Japan, the sources said.
Now tell me: Why would North Korea or Russia put any deliveries between them in jeopardy by transferring them via a third party far away from their areas of influence and operation?
They won't.
My hunch is that Russia does not buy ammunition from North Korea. But it could do so. North Korea has, in constant preparation for war, over decades accumulated lots of ammunition that is getting old and should be replaced by newer one. To sell off the old stuff for cheap would be a rational move. Russia is unlikely to need it but, if the price is right and the quality still acceptable, there is no reason to reject any such offer.
Most likely though the Biden administration is just making this up to somehow put Russia as well as North Korea into a bad light.
As the Russian president Vladimir Putin explained:
I already said that the dictate of the Western countries and their attempts to apply pressure on all the participants of international communication, including countries that are neutral or friendly to us, are achieving nothing, and they are looking for additional arguments to convince our friends or neutral states that they all need to confront Russia collectively.
The U.S. public and some dull inhabitants of U.S. colonies in Europe may well fall for such nonsense. But no one outside of that closed club will believe such claims without being shown some reasonable evidence.
There is of course none.