Duda made the statement during a visit to Montenegro, at a joint news conference with the Balkan country's head of state, Milo Djukanovic.
Asked by reporters about the migrant crisis and German Chancellor Angela Merkel's recent conversation about it with Belarusian strongman leader Alexander Lukashenko, Duda said that "Poland won't accept any decisions taken above our heads, so to speak" amid the border standoff.
Duda said he communicated his concerns to his German counterpart Frank-Walter Steinmeier when they talked on the phone on Tuesday, Poland's PAP news agency reported.
"Any settlements that would be binding for Poland and for our authorities can only be made by ourselves," Duda told reporters, as quoted by the Polish state news agency.
"We are a sovereign country which is entitled to make its own decisions, and we are going to exercise this right, no matter what," the Polish president also said.
He emphasised that "the Belarusian regime is manipulating and pushing migrants towards the Polish frontier," while Warsaw has a duty to protect the European Union's external border against illegal migration, PAP reported.
Visit to Montenegro
In the Montenegrin city of Cetinje, Duda on Wednesday spoke to Djukanovic about the border crisis as well how Poland and Montenegro can work together in NATO.
He also declared that "Poland supports Montenegro's aspirations to join the European Union," his presidential office announced.
The two heads of state spoke privately before leading broader talks between Polish and Montenegrin government officials, aides said.
As he continues his Balkan trip, the Polish president is set to visit North Macedonia later this week.
Migrant crisis
The migrant crisis on the Polish-Belarusian border has grown since the summer, with Poland, the European Union and its member states, as well as NATO and the United States accusing Alexander Lukashenko, the autocratic leader of Belarus, of orchestrating the standoff in retaliation for Western sanctions against his regime.
EU foreign ministers on Monday gave the green light for a widening of the sanctions in response to Minsk's actions.
Lukashenko has denied luring vulnerable people, including Kurds from the Middle East, with the false promise of easy access to the EU and sending them over the bloc's border.
Tensions at Polish-Belarusian border
Poland's Border Guard said on Wednesday it had recorded 161 illegal attempts to cross from Belarus over the past 24 hours. Since the start of the year, over 33,000 such attempts have been recorded, the PAP news agency reported.
On Tuesday, the border standoff turned violent as migrants pelted Polish forces with rocks and stun grenades near the checkpoint in Kuźnica, officials told reporters.
Since September 2, Warsaw has kept the border zone under a state of emergency in the face of the migrant pressure.
Poland plans to build a solid fence along the Belarus frontier, crowned with barbed wire and fitted with electronic surveillance devices. The protective wall is due to be ready by mid-2022.
EU, NATO, US, UN nations condemn Belarus
The United States has called on Russia to use its influence over Belarus "to cease its callous exploitation and coercion of vulnerable people," White House spokeswoman Jen Psaki said this week amid the deepening migrant crisis on the Polish-Belarusian border.
US State Secretary Antony Blinken at the weekend reaffirmed America's support for Poland amid the crisis on the EU member's border with Belarus.
The United States and European members of the UN Security Council last week condemned Belarus for the “orchestrated instrumentalization" of migrants as tensions rose along the Polish-Belarusian border.
The Polish prime minister has said that NATO must take steps to help resolve the crisis on the Belarus border, adding that Poland and the Baltic states of Lithuania and Latvia may ask for consultations under Article 4 of the alliance's treaty.
Polish lawmakers on Wednesday passed legislation to strengthen the country's frontiers amid simmering tensions on the border with Belarus.
(pm/gs)
Source: PAP, prezydent.pl, TVP Info