Tusk arrived in Paris as part of a mini-tour that later sees him travel to Berlin seeking closer ties with Europe's two largest powers as the war in Ukraine enters its third year and Europe's capitals eye the possibility of Donald Trump returning to the White House.
Trump sparked outrage among Western partners at the weekend after suggesting the United States might not protect NATO allies who are not spending enough on defence from a potential Russian invasion.
"There is no alternative to the EU, NATO, transatlantic cooperation. Europe must become a safe continent, and this means that the European Union, France and Poland must become strong and ready to defend their own borders and to defend and support our allies and friends from outside the Union," Tusk said in a joint statement with French President Emmanuel Macron.
Dobrze Cię widzieć — Donald Tusk (@donaldtusk) @EmmanuelMacron! pic.twitter.com/xLdh4DMrMSFebruary 12, 2024
"It is probably here in Paris that the words from 'The Three Musketeers' by Alexandre Dumas resonate most clearly: 'All for one, and one for all'," he said, referring to Dumas' novel.
Warsaw, Paris and Berlin see EU unity on defence and a ramping up of the 27-member states' support for Ukraine as crucial at a time when U.S. backing of Kyiv is wavering amid political infighting in Washington.
"Europe has to get its act together ... This is a matter of answering a question about what will happen if Trump wins. We don't have time. We must have bigger defence industry capacity," said a Polish government source.
The source added that Europe urgently needed joint production of ammunition and that Poland was no longer blocking "strategic autonomy" - making Europe less dependent on others.
The shift has been noticed elsewhere in Europe.
"Now for the first time a Polish government is saying that strengthening the European Security Defence Capabilities area is not a contradiction to a strong NATO," said Dietmar Nietan, a German official in charge of cooperation with Poland.
Relations between Poland and Germany were strained by eight years of nationalist rule in Warsaw. The campaign for October's Polish election saw the Law and Justice (PiS) party, in power from 2015 to 2023, cast Berlin as villain on everything from migration to energy.
However, analysts say the return of former European Council President Tusk to prime minister makes it easier to reinvigorate the "Weimar Triangle" platform of political cooperation between Germany, France and Poland created in 1991.
