"Another leak is another proof that this is a deliberate act, an act which, I think, certainly has the right to be called a terrorist act," the top diplomat told reporters at the Seimas on Thursday.
His comment followed reports by the Swedish Coast Guard that a fourth leak from the Nord Stream pipelines has been detected in the Baltic Sea.
Earlier this week, after seismologists reported explosions at the Nord Stream pipelines, European leaders said that sabotage was the most likely cause of the leaks in these Baltic Sea pipelines connecting Russia and Europe.
The culprit is believed to be Russia as it wants to escalate the war in Ukraine. But the Kremlin rejects the accusations, saying it is "stupid and absurd" to blame Russia for causing the leaks.
Landsbergis says such actions are aimed at creating fear and making it more difficult to supply Europe with gas.
"All of this meets the definition of a terrorist act, at least from a political point of view, but a legal assessment will be done later," the minister said.
The UN Security Council is scheduled to discuss the issue on Friday.