Leaders around the Baltic Sea reacted warily Wednesday to reports that Russia could revise the borders of its territorial waters in the region, with Lithuania’s foreign minister calling it an “obvious escalation” that must be met with an “appropriately firm response.”

In a draft proposal reported by some Russian media, Russia’s Defense Ministry suggests updating the coordinates used to measure the strip of territorial waters off its mainland coast and its islands in the Baltic Sea. The existing coordinates were approved in 1985, the ministry says, adding they were “based on small-scale nautical navigation maps” and don’t correspond to the “modern geographical situation.”

It wasn’t immediately clear from the draft whether the proposed changes would shift the border or merely clarify it.

Swedish Prime Minister Ulf Kristersson noted that Russia had signed a United Nations convention regulating such changes. “Both we and Finland assume that Russia — which is a signatory party to that convention — lives up to that responsibility,” he said, according to Swedish news agency TT.

If Russia were to challenge borders, “then Russia violates a U.N. convention, then Russia has the whole world against it,” Finland’s Foreign Minister Elina Valtonen said, according to Finnish broadcaster YLE. She noted, however, it was likely a routine act by Russia and not a provocation.

Finnish President Alexander Stubb wrote on X that Russia had not been in contact with Finland on the matter. “Finland acts as always: calmly and based on facts,” he wrote.

Also on X, Lithuanian Foreign Minister Gabrielius Landsbergis asserted that Russia was “attempting to spread fear, uncertainty, and doubt about their intentions in the Baltic Sea.” There has been great concern in Lithuania about Russian troops’ latest gains in northeastern Ukraine.

German Defense Minister Boris Pistorius, who was on a visit to Lithuania on Wednesday, echoed Landsbergis’ remarks, saying that “whatever this was or actually is, it appears to be another example of the thoroughly perfidious kind of hybrid warfare that Putin is practicing,” German news agency dpa reported.

The Baltic News Service reported that Lithuania summoned the Russian representative for a detailed explanation.

However, Russia’s Interfax news agency later Wednesday cited an unnamed military diplomatic source saying Moscow does not intend to revise the border or the width of its territorial waters.

Kremlin spokesman Dmitry Peskov told reporters there was “nothing political” in the Defense Ministry’s proposal. “You see how tensions and the level of confrontation are escalating, especially in the Baltic region. This requires appropriate steps from our relevant bodies to ensure our security,” Peskov said.

The proposal was published on an official government website for draft legislation but appeared deleted Wednesday. It wasn’t immediately clear why.

Since Russia’s full-scale invasion of Ukraine in early 2022, Finland and Sweden have joined NATO. The Baltic Sea — Russia’s maritime point of access to the city of St. Petersburg and its Kaliningrad enclave — is now almost surrounded by members of the military alliance.

Kaliningrad is sandwiched between Lithuania to the north and east and Poland to the south. It is home to the Russian Navy’s Baltic Fleet, making it a strategically significant area for Russia.

This potential shift in territorial waters comes at a time of heightened geopolitical tensions and underscores the complex military dynamics in the Baltic region. The region’s countries, particularly NATO members, are closely monitoring these developments, wary of any actions that could further destabilize the area. The geopolitical landscape of the Baltic Sea is thus a crucial factor in European security, and any changes or perceived threats by Russia are met with significant concern by neighboring states and NATO allies.

Moreover, the situation reflects the broader context of Russia’s aggressive foreign policy maneuvers and the strategic importance of the Baltic region in the ongoing power struggle between Russia and the Western alliance. As such, any potential revision of territorial waters is not merely a regional issue but a matter of international security, requiring coordinated diplomatic and strategic responses from the global community. The developments highlight the delicate balance of power in the Baltic Sea, a region where historical tensions and modern geopolitical strategies intersect.