WASHINGTON — US Secretary of State Marco Rubio and tech billionaire Elon Musk have had a contentious exchange with Polish Foreign Minister Radoslaw Sikorski, in a series of X posts on Sunday over the use of Musk's Starlink satellite system in Ukraine.

In a response to a post from Musk mentioning turning off the system, Sikorski implied that any threats to shut down Starlink would result in a search for other suppliers.

Rubio quickly dismissed the claims that Musk would shut down the system and urged Sikorski to be grateful.

The trio went back and forth in an exchange of posts on X that ended with Musk calling Sikorski "small man".

Starlink's system is part of SpaceX's mission to provide high-speed internet to remote and underserved areas — like war zones — around the world.

Sunday's exchange started when Musk posted that Starlink was the "backbone of the Ukrainian army".

"Their entire front line would collapse if I turned it off," he wrote.

Sikorski then responded to Musk's post, saying that Poland was paying for the service.

"Starlinks for Ukraine are paid for by the Polish Digitization Ministry at the cost of about $50 million per year," Sikorski wrote. "The ethics of threatening the victim of aggression apart, if SpaceX proves to be an unreliable provider we will be forced to look for other suppliers."

Sikorski's post caused Rubio to chime in, writing that the Polish foreign minister was "just making things up".

"No-one has made any threats about cutting Ukraine off from Starlink," Rubio wrote.

"And say thank you because without Starlink Ukraine would have lost this war long ago and Russians would be on the border with Poland right now," he added.

Musk later responded to Sikorski's post calling him a "small man".

"Be quiet, small man. You pay a tiny fraction of the cost. And there is no substitute for Starlink," Musk wrote.

The Starlink terminals are key to Ukraine's army operations and have been used since the start of the Russian invasion in February 2022.

There are tens of thousands of terminals in the country, including up to 500 purchased by the US Department of Defense in June 2023. — BBC