A staff member hangs a US national flag before US President Joe Biden arrives for the European Council meeting in Brussels, Belgium, March 24, 2022. [Photo/Xinhua]

ROME - The eastward expansion of the US-led North Atlantic Treaty Organization (NATO) toward Russia is a major root cause of the ongoing conflict between Russia and Ukraine, which could take a heavy toll on the European economy, an Italian economist has said.

NATO EXPANSION RED LINE FOR RUSSIA

Michele Geraci, former undersecretary of state at the Italian Ministry of Economic Development, told Xinhua in an exclusive interview that the military alliance's moves have created two main problems for Russia.

"From the Russian point of view, NATO's expansion into eastern Europe is a breach of a promise" made in the 1990s, Geraci said.

"Second, Russia considers this expansion a threat to its territorial integrity and national security, so President (Vladimir) Putin for the last ten years has been saying that this is not acceptable, and that NATO has crossed a red line."

"Every country has its own red lines. For Russia, the red line was having NATO at its borders," he said.

NATO has gone through five rounds of enlargement to the east since 1999, increasing the number of its members from 16 to 30 and reaching the Russian border.