Russia considers the US plan to annex Greenland "serious" and is concerned that the West could use the Arctic as a springboard for future conflicts, Russian President Vladimir Putin said on Thursday.
US President Donald Trump has sought to take control of the autonomous Danish island since taking office in January, saying Washington must have it for "international security".
"It is a gross mistake to think that this is an extravagant discussion by the new American administration. It is nothing like that," Putin said at an Arctic forum in the northern city of Murmansk.
"We are talking about serious plans from the American side regarding Greenland. These plans have long-standing historical roots," he added.
He revealed that Russia was not directly involved in the Greenland ownership issue, but Moscow was concerned that "NATO countries, in general, are increasingly defining the far north as a springboard for potential conflicts."
Putin said that NATO member countries have been conducting an increasing number of military exercises in the Arctic.
He said Russia "has never threatened anyone in the Arctic," but "we are watching recent developments closely."
Saying that "the number of military personnel in the Arctic will increase," he adds: "We are developing our response capabilities by improving our military infrastructure."
"We will not allow the sovereignty of our country to be violated, we will defend our national interests," he further said.
However, he went on to talk about the potential for cooperation with "friendly states...possibly including Western countries" in the Arctic region.
"I am confident that the time for such projects will definitely come," he said.
Greenland, which is seeking independence from Denmark, is already home to a US military base, which US Vice President JD Vance will visit on Friday.
The island is strategically located between North America and Europe at a time of growing interest from the US, China and Russia in the Arctic, where sea lanes have opened up due to climate change.