The Taoiseach will today meet EU leaders in Brussels amid fears European unity on sanctions against Russia is "starting to crumble".
A proposed ban on Russian oil imports looks unlikely to be agreed, with Hungary continuing to block the measure.
The move to ban the purchase of Russian oil to cut funds for the war in Ukraine has been held up for the past four weeks by several countries including Hungary.
They have warned that their economies are totally dependent on oil piped in from Russia and replacing the system would cost hundreds of millions of Euro.
Diplomats are now working on a watered-down proposal which would ban tanker imports of oil but allow importation to continue for countries with a direct pipeline to Russia.
That would mean the embargo only applies to two-thirds of the oil from Russia.
That proposal is likely to cause anger as it would leave some countries searching for expensive alternatives to Russian oil while others - including Poland, Germany, Hungary and Slovakia - continue to accept oil through pipelines.
Yesterday the German Economy Minister Robert Habeck called on EU nations to stand together, warning that unity on the response to the war was “starting to crumble”.
EU ambassadors are meeting this morning in a last-minute attempt to get a deal over the line before EU leaders meet this afternoon.
Micheál Martin is travelling to the summit from Lebanon via Istanbul.
Ukraine, energy, food security and defence are the main items on the agenda for European leaders.
They will discuss the ever-increasing rise in fuel and food costs, while Ukrainian President Volodomyr Zelensky will address the gathering by video link to encourage the EU to do more.
With reporting from Sean Defoe.