A Russian invasion of Ukraine would be "very difficult for the world as a whole to deal with" the Taoiseach has warned.
Speaking in the Dáil, Micheál Martin said the Government wanted to see a "diplomatic resolution" to the current crisis.
"We want to see it de-escalated. We don't believe it necessitates the amassing of so many hundreds of thousands of troops, it doesn't necessitate a war or an invasion, or the violation of Ukrainian territory, integrity, and that is clear."
Mr Martin added that the world would breathe a "collective sigh of relief" if the situation is de-escalated.
"The world is trying to come through Covid-19 and all its implications, and now to go through another crisis, which could occur as a result of an invasion, I think would be very, very difficult for the world as a whole to deal with."
He said that Russia's plan to carry out military exercises in international waters off our coast, is "not welcome and is not helpful".
Mr Martin added that there would be "other implications" around marine life and biodiversity if the exercises go ahead.
Earlier, the Tánaiste warned fishermen planning to peacefully disrupt Russia’s military exercises off the coast of Ireland not to put themselves at risk.
Patrick Murphy, chief executive of the Irish South and West Fish Producers Organisation, said some of its members plan to hold a peaceful protest against the military exercises next month.
The artillery drills at the start of February will take place in international waters but within Irish-controlled airspace and the country’s exclusive economic zone (EEZ).
Mr Murphy said the area is “very important” for fishing and they want to protect biodiversity.
On Monday, the Russian ambassador to Ireland said plans to hold navy military exercises off the coast of Ireland are a “non-story”.
Yury Filatov downplayed the significance of the exercises, after concerns were raised by the Irish Government.
Foreign affairs minister Simon Coveney said they were “not welcome”.
When asked about the fishermen’s plans, Tanaiste Leo Varadkar said on Tuesday: “I haven’t had the chance to speak to any of the fishermen operating in that area.
“I suppose I would just say to them that these are military vessels. Whatever they choose to do in terms of any protests, just make sure that they don’t put themselves at risk.”
Mr Varadkar said that the military exercises are happening outside Ireland’s territorial waters, leaving Ireland with no power to prevent them from happening.
“But we have made it very clear that these exercises are not welcome, particularly in the current context, when tensions are rising in relation to Ukraine,” Mr Varadkar added.
“That’s being communicated to them very strongly. There are no plans to send Irish troops to Ukraine, that hasn’t been discussed.”
Mr Varadkar said the Cabinet received a comprehensive briefing from Mr Coveney over fears that Russia will invade Ukraine.
“It is very serious, there is a real fear that we could see a land war on the continent of Europe,” the Fine Gael leader added.
“We haven’t seen that for a very long time.
“Aside from the humanitarian impact, it could have an impact on us economically as well.
“We got a comprehensive briefing on that today. We’re co-ordinating our response, of course, with our European partners and our UN partners.
“The Russian exercises off the coast of Cork and Kerry, while not illegal, are not welcome.
“We don’t believe that they’re connected to the events in Russia and Ukraine, but we certainly would prefer that they were not happening.”
In compliance with legal requirements, Russia informed Ireland’s aviation authorities of the planned activities in advance.
The Irish Aviation Authority (IAA) said there would be no impact on the safety of civil aircraft operations.