Poland said on Tuesday it would impose temporary checks on its borders with Germany and Lithuania starting on July 7.

Polish Prime Minister Donald Tusk said that the measure was aimed at reducing irregular migrant crossings.

"We consider the temporary restoration of controls at the Polish-German border necessary to limit and reduce to a minimum the uncontrolled flows... of migrants back and forth," Tusk said, adding that similar checks would be imposed on the Lithuanian border.

"We are aware that this decision entails certain consequences regarding the freedom of movement of people... There is no other way," Tusk added.

Merz says Germany and Poland have a 'common problem'

Meanwhile, German Chancellor Friedrich Merz rallied against criticism from neighboring countries over his border policies.

"We must at this time keep border controls, because the protection of the external European borders is not sufficiently guaranteed," Merz said in Berlin, shortly after Tusk announced checks on the border with Germany would begin next week.

Merz said that he had discussed the issue with his opposite number in Poland on several occasions and that the two leaders want to work together on the issue. "We have a common problem here that we want to solve together," he said.

He also firmly rejected Polish media reports claiming that asylum seekers who have already been accepted in Germany are being returned to Poland. 

"Some people here are claiming that there is a kind of repatriation tourism from Germany to Poland and that they are then practically being taken back across the border to Poland," said the chancellor, who took office in May. That is not the case."

Economic cooperation within EU must be maintained, says Luxembourg's Frieden

Speaking at a meeting with Luxembourg's Prime Minister Luc Frieden in the German capital, Merz said the newly installed controls would not be permanent and that disruption is being kept "as small as possible" for cross-border commuters, a major issue in landlocked Luxembourg. 

"We do not want to hinder those who commute daily," said Merz. 

Frieden called for increased police cooperation to reduce or get rid of controls, adding that he stands by "the principle that illegal immigration is intolerable" but insisted that economic cooperation within the EU's internal borders must not be disrupted.

"We both value the freedom of movement in the Schengen area and want to preserve it. This only works if it is not abused. Therefore, we must combat irregular migration — together and as Europeans," the German Chancellor posted on X.

Edited by: Jenipher Camino Gonzalez