BUCHAREST (Reuters) - Romania, Bulgaria and Greece signed a deal on Thursday to enable swift cross-border movement of troops and weapons to NATO's eastern flank, Romania's defence ministry said.

Russia's 2022 invasion of Ukraine has increased the urgency both for NATO and the European Union to speed up preparations, including the ability to quickly send reinforcements, in case of a sudden conflict with Moscow. NATO has told its members that too much red tape is hindering troop movements across Europe.

The planned harmonized military mobility corridor between the three NATO and EU states was one of two such mobility corridors agreed on the sidelines of the NATO summit in Washington.

It aims "to optimize transport corridors to respond to military mobility needs by creating road and rail supply lines between the participating states, reducing peace time bureaucracy and maximizing efficiency in case of emergency situations," the Romanian ministry said.

The three states could also connect their ports in the Aegean and Black seas.

Romania and Bulgaria are already a part of a joint effort with Turkey to defuse stray mines in the Black Sea.

On Thursday, the Romanian and Bulgarian defence ministers also signed a memorandum to establish a regional special operations command centre which will plan and manage the Alliance's special operations forces in the Black Sea region.

(Reporting by Luiza Ilie; Editing by Peter Graff)