MOSCOW (AP) — Russian President Vladimir Putin on Monday marked the date of the Nazi invasion of the Soviet Union by meeting with veterans and visiting a new military church.

Putin laid a wreath at the Tomb of the Unknown Soldier at the Kremlin wall and greeted World War II veterans.

He also visited the newly built main cathedral of the Russian military on Moscow's western outskirts.

Nazi Germany invaded the USSR on June 22, 1941, starting nearly four years of fighting that killed 27 million Soviet people and left the western part of the country in ruins.

“It was a terrible and massive tragedy that claimed millions of lives, leaving behind devastation and irreparable pain of loss, deep never-healing wounds,” Putin said, addressing soldiers outside the cathedral.

Victory Day, marking the Nazi defeat in World War II, is Russia's most important secular holiday, celebrated on May 9. This year, the Red Square military parade marking it was postponed because of the coronavirus pandemic and will be held Wednesday.