The meeting took place prior to an informal summit of the Arraiolos Group's heads of state.
The September 14-15 get-together in Valletta is being attended by the presidents of Austria, Bulgaria, Croatia, Estonia, Greece, Latvia, Germany, Poland, Portugal, Slovenia, Hungary, Italy and Malta.
See also: Polish and German presidents meet in Malta Andrzej Duda's talks with the pair of Maltese leaders concerned bilateral matters, his top aide Krzysztof Szczerski said.
These included developing stronger economic relations, security issues, as well as collaboration on the international stage, in line with the European Union's current agenda
- President Duda: Open door to new members key for EU survival
President Andrzej Duda during a meeting of the Arraiolos Group in Valletta, Malta, voiced his support "for an open door policy since the EU needs more countries to be economically competitive".
"If the EU closes its doors to new members, it will probably disintegrate", the Polish head of state stressed.
Addressing a panel devoted to economic development, President Duda underscored that Europe was one of the wealthiest regions in the world and its living standards were much higher than in many other places globally.
But the Polish head of state admitted that the economic centre of gravity, "was clearly shifting outside Europe".
"Since the Asia Pacific region generates around 40 percent of global GDP, Europe must find a way not to allow its position to gradually weaken", the Polish president went on.
President Duda noted that it was Brexit that currently undermined the EU. "The great British economy is leaving, the results of which are difficult to predict. If one of the EU societies says 'no' to the Union, it by all means bears testimony to the fact that the great European project has lost its allure", he added.
According to the Polish head of state, an open door policy is fundamental for the EU to survive.
"In the years or decades to come, we need new countries in the EU to continue being competitive", he emphasised.
"We need those countries that are still aspiring to join the EU. We must keep telling them that the door to the EU is open; if you meet the criteria, you will be accepted since this is the only way to build the EU's potential. If we close the door to the EU, the Union will probably disintegrate, and we all will lose out", President Duda said, concluding that "if we want to produce, we need more markets as ours are insufficient".
The Arraiolos Group was launched in October 2003 when then Portuguese President Jorge Sampaio hosted his counterparts in a town of that name.
In 2013, the get-together took place in the Polish city of Cracow.
The Arraiolos Group comprises presidents of EU countries who do not wield direct executive power in their states. (PAP)