President Trump attacks CNN on a regular basis. But he usually focuses on the domestic side of the network — his least favorite cable news station — making his post on Twitter this weekend about CNN’s international arm something of a rarity.

“@FoxNews is MUCH more important in the United States than CNN, but outside of the U.S., CNN International is still a major source of (Fake) news, and they represent our Nation to the WORLD very poorly,” Mr. Trump wrote on Saturday. “The outside world does not see the truth from them!”

Also notable: Mr. Trump’s comments came hours after President Vladimir V. Putin signed a law that requires certain American media outlets working in Russia to register with the government as foreign agents, essentially identifying them as hostile entities. Mr. Putin’s allies had previously signaled that CNN International could be affected.

For now, CNN appears untouched by the new regulations in Russia. But with an ongoing investigation into possible ties between allies of Mr. Trump and Mr. Putin, the timing and content of Mr. Trump’s tweet were quickly dissected for potential hints at a connection. Was this a sign that the two had united against a common foe?