Jakub Kumoch, who is the top foreign policy advisor to President Andrzej Duda, made the remark in an interview with Polish state news agency PAP on Monday.
Kumoch said that Ukraine’s proposal to give special rights to Poles in Ukraine showed “how close Poland and Ukraine have become.”
He added: "As for the date when the bill was sent to parliament, it’s unlikely to have been a coincidence."
Ukraine’s President Volodymyr Zelensky submitted the draft legislation when Poland on Monday marked its National Day of Remembrance of Victims of Genocide by Ukrainian nationalists against Poles during World War II.
Kumoch said: “Radical Ukrainian nationalists tried to drive Polish people away from the land that they regarded as Ukrainian, and today, Poles are being symbolically invited to Ukraine again, to be treated in the same way as citizens of Ukraine.”
"It’s a great thing," he added.
Earlier on Monday, President Duda said that the new regulations represented Ukraine’s “symbolic invitation” to the Polish people.
Legal stay, right to work, access to public services
Under Zelensky’s bill, Poles in Ukraine would enjoy rights and guarantees similar to those Poland has granted to Ukrainians fleeing the Russian invasion, according to officials.
Polish citizens would be allowed to stay legally in Ukraine for 18 months after the bill is enacted. They will also be able to work, do business, study, use healthcare services and claim certain social benefits in Ukraine, reporters were told.
Also on Monday, Zelensky granted the title of "Rescuer City" to Przemyśl in southeastern Poland for its role in helping war-torn Ukraine and welcoming refugees.
Earlier, a similar honour was given to Rzeszów, another southeastern Polish city, the PAP news agency reported.
Tuesday is day 138 of the Russian invasion of Ukraine.
Source: PAP, rmf24.pl, prezydent.pl
Click on the audio player above for a report by Radio Poland's Michał Owczarek.