In a statement for the PAP news agency, Andrzej Duda said that “the use of chemical weapons on the territory of our strategic ally cannot be left unanswered.”
He also said that Poland would “work closely with the United Kingdom on this issue within the UN Security Council and as part of NATO, the European Union and the Organisation for the Prohibition of Chemical Weapons.”
Sergei Skripal, a former Russian intelligence agent convicted of spying for Britain, is believed to have been poisoned with deadly Novichok nerve gas in Salisbury, a quiet town in southern England near the famous ancient ruins of Stonehenge, according to reports.
According to the Politico news service, at least two people, Skripal and his daughter Yulia, “have been left extremely sick due to the alleged nerve agent.”
Both are reported to be in critical condition in a local hospital.
A former agent with Russia’s FSB security service, Colonel Skripal arrived in Britain in 2010 as part of a prisoner exchange, according to The Telegraph daily. Prior to that he was jailed in Moscow for spying for Britain, the British newspaper has reported.
The Polish president said in his statement on Wednesday that he “was deeply concerned about the brutal and shocking attack on the Skripal family, in which a British police officer was also hurt."
Speaking "on behalf of all Poles and the Polish authorities,” Duda also expressed his solidarity "with the actions undertaken” by UK Prime Minister Theresa May.
Earlier, politicians including US President Donald Trump, French President Emmanuel Macron and German Chancellor Angela Merkel declared support for the British government in telephone conversations with May amid a dispute with Russia over the Salisbury attack.
Donald Tusk, the head of the European Council, the EU’s top political authority, said he would put the issue on the agenda for a summit of European Union leaders in Brussels next week.
A senior aide to the Polish prime minister said on Wednesday that Poland was ready to help the UK solve the case of the suspected poisoning.
May said on Monday it was “highly likely” that Russia was responsible for the March 4 attack in Salisbury. She also gave Moscow a deadline to provide explanations by Wednesday.
Moscow has denied allegations of Russian involvement.
Britain to expel 23 Russian diplomats
May on Wednesday announced the expulsion from Britain of 23 Russian diplomats believed to be involved in espionage-related activities. Speaking to Parliament, she also announced a series of other measures against Moscow over the Salisbury attack, including a halt to meetings with senior Russian officials.
Earlier in the day, Britain’s Foreign Office called for an urgent meeting of the UN Security Council over Russia’s role in the suspected nerve gas attack.
NATO expresses 'deep concern'
Meanwhile, NATO, the Western defence alliance, "expressed deep concern at the first offensive use of a nerve agent on Alliance territory" since the organisation was founded in 1949.
"The UK confirmed the use of a military-grade nerve agent of a type developed by Russia and briefed Allies that it was highly likely that Russia was responsible," the North Atlantic Council, NATO's top decision-making body, said in a statement on Wednesday. "The UK also confirmed that this was an indiscriminate and reckless attack against the United Kingdom, putting the lives of innocent civilians at risk."
The North Atlantic Council called Russia "to address the UK’s questions including providing full and complete disclosure of the Novichok programme to the Organisation for the Prohibition of Chemical Weapons."
The statement also said that "NATO regards any use of chemical weapons as a threat to international peace and security."
Source: PAP, nato.int