It's warned two Russian ships - currently in Irish waters - could try to destroy critical underwater cables connecting Europe and the US.
The Irish Air Corps and Naval Service are monitoring the Russian state-owned vessels, which are currently in waters off the south-west coast.
The two Russian flagged ships, the Umka and the Bakhtemir, caused alarm among defence officials late last week, The Irish Times reports.
The concern came after the ships were spotted engaging in unusual manoeuvrers off the Galway coast, in the vicinity of a newly opened subsea communications cable.
It comes as Russia takes over the rotating presidency of the UN Security Council this weekend.
Security analyst and independent senator Tom Clonan explained the significance of these subsea cables in an interview with Newstalk.
"So these are the fibre optic cables that basically connect the European Union to the United States. Something like one third of all of the data online, everything on the internet, goes through these cables... so they are a really critical piece of infrastructure and we have to be mindful of their presence."
Yuriy Filatov, Russia’s ambassador to Ireland, has criticised reports around the ships.
He told The Irish Times: “The purpose of this story seems to be to once again create an impression of ‘suspicious’ Russian maritime activity, allegedly aimed at sabotaging subsea communication cables.”