Warsaw to mark 80 years after WWII outbreak

US Vice President Mike Pence will take his place in Warsaw for the anniversary of the start of history's bloodiest conflict, which claimed more than 50 million lives including six million Jews in the Holocaust.

Also not coming are French President Emmanuel Macron and British Prime Minister Boris Johnson, while Russian President Vladimir Putin was not invited -- unlike 10 years ago -- because of Moscow's 2014 annexation of Crimea from Ukraine.

"This should be an event that unites people," said political analyst Marcin Zaborowski, adding that Warsaw should have included Russia and tried harder to attract other leaders instead of focusing on Trump.

"He cancelled and the whole thing is now looking of lesser importance," he told AFP.

The Polish presidency has said it expects around 40 foreign delegations, half of them led by heads of state.

They include Ukrainian President Volodymyr Zelensky whose partnership matters to Poland, which believes its security depends on Ukraine remaining outside of Russia's sphere of influence.

First bombs at dawn

On August 23, 1939, Germany and the Soviet Union secretly agreed to carve up Eastern Europe between them by signing the Molotov-Ribbentrop Pact.

World War II began a week later on September 1 when a Nazi German battleship opened fire on a Polish fort in Westerplatte in the Baltic Sea. That same morning the Nazis also bombed the central city of Wielun.

At dawn on Sunday, Polish President Andrzej Duda and his German counterpart Frank-Walter Steinmeier will attend a remembrance in Wielun.

Polish Prime Minister Mateusz Morawiecki and European Commission Vice President Frans Timmermans will take part in a ceremony in Westerplatte, a peninsula of the port city of Gdansk.

Pence and the presidents of Poland and Germany will deliver speeches at the ceremony in Warsaw's Pilsudski Square, the site of the Tomb of the Unknown Soldier.

Poland suffered some of the worst horrors of World War II: nearly six million Poles -- half of them Jews -- died in the conflict.

Hitler's attack on Poland led Britain and France to declare war on Nazi Germany. On September 17, the Soviet Union in turn invaded Poland.

After the Nazis tore up the pact with Moscow, two alliances battled it out to the end: the Axis powers led by Germany, Italy and Japan and the victorious Allied forces led by Britain, the Soviet Union and the United States.

Though it has been 80 years since the war started, there are still unresolved matters according to Poland, which says Germany owes it war reparations.

A parliamentary commission is currently working on a new analysis of the extent of Poland's wartime human and material losses. Berlin, however, believes the case is closed.

Trump a no-show

Had he come, Trump would have been the first US president to attend Polish commemorations of the outbreak of the war.

The Polish president's chief of staff, Krzysztof Szczerski, said Friday that the visit was postponed, not cancelled.

"It's very understandable and obvious that in such a situation the president who is also responsible in the US for emergency situations should be there and wants to be there," Szczerski told the news channel TVN24.

Trump had been due to sign a joint document in Poland regarding the June decision to send an additional 1,000 US troops to Poland as a counter against possible Russian action.

Around 5,000 US soldiers are already deployed along with NATO forces in Poland.

Polish Defence Minister Mariusz Blaszczak said Friday the document signing "has been postponed to when Donald Trump visits".

Former Polish leftist premier Leszek Miller said Trump's annulment was a blow for the governing right-wing Law and Justice (PiS) party ahead of October's general election.

"PiS had wanted to turn this visit into a key element of its propaganda campaign. So in terms of votes, it is a problem," he told the WP.pl website.

Robert Biedron, the leader of the progressive Spring party, for his part criticised the PiS for prioritising US relations over all others.

"This was a mistake that has left us completely marginalised in the European Union," he said.