(20)In the event of a sudden disruption of oil supplies, whether by pipeline or seaborne, Member States should act in a spirit of solidarity and regional cooperation, involving both public authorities and energy undertakings, in close coordination within the Oil Coordination Group, with a view to possible releases of oil stocks, including emergency oil stocks, and other measures, including the supply of the appropriate blend, as foreseen in their national contingency plans or agreed in accordance with Directive 2009/119/EC. This commitment of solidarity and cooperation is of particular relevance in view of Russia’s aggression on Ukraine and a possible disruption of supplies of Russian crude oil or refined petroleum products in the region, in particular regarding pipelines or Black Sea ports. The Commission will monitor markets and the security of supply, and will report to the Council on a regular basis and, if necessary, make proposals to strengthen the security of supply.