German President Frank-Walter Steinmeier (right) welcomes Polish President Andrzej Duda in Berlin. Odd Andersen/AFP

Germany is marking the 30th anniversary of the opening of the Berlin Wall, a pivotal moment in the events that brought down Communism in eastern Europe.

Leaders from Germany and other European nations are attending ceremonies on Saturday in Berlin recalling the peaceful protests that piled pressure on East Germany's government to allow its citizens free passage to the west on Nov. 9, 1989.

People gather ahead of a ceremony marking the 30th anniversary of the fall of the Berlin Wall in Berlin, Germany. Reuters

The main commemoration is being held at Bernauer Strasse, where one of the last parts of the Berlin Wall that divided the city for 28 years still stands.

Light installations, concerts and public debates are also being held throughout the city and other parts of Germany to mark the anniversary.

Germany on Saturday marks 30 years since the fall of the Berlin Wall that ushered in the end of communism and national reunification, as the Western alliance that helped secure those achievements is riddled with divisions.

Two days before the date that brought epochal change, France's President Emmanuel Macron dropped a bombshell, declaring that transatlantic partnership NATO was suffering from "brain death" and that Europe itself was "on the brink".

This photo shows the Berlin Wall memorial site at Bernauer Strasse in Berlin, Germany, on Saturday. AP

Chancellor Angela Merkel responded with uncharacteristic sharpness, saying Thursday "I don't think that such sweeping judgements are necessary", and the ensuing storm over NATO laid bare the growing differences among traditional allies.

The bad tempered prelude to the festivities stood in sharp contrast to celebrations five years ago, when former Soviet leader Mikhail Gorbachev and ex-Polish president and freedom icon Lech Walesa were present.

This time, leaders of former Cold War powers will be absent, as Donald Trump's America First policy, Britain's Brexit struggles and Russia's resurgence put a strain on ties.

US Secretary of State Mike Pompeo's visit ended Friday while Macron is only planning a flying visit on Sunday, leaving the actual anniversary on November 9 without globally prominent figures.

Pompeo also left behind a stark warning: "As we celebrate, we must also recognise that freedom is never guaranteed.

"Today, authoritarianism is once again rising," he said, namechecking China and Russia.