WARSAW, Poland—German Chancellor Angela Merkel said Saturday that she found it unacceptable that refugees were being used to apply pressure to Poland and other European Union members on the border with Belarus. Speaking at a news conference during what she said she expected to be her last official visit to Poland as chancellor, Merkel appealed to Belarus, but also to Poland, to help people in difficult humanitarian conditions caught between the border of Poland and Belarus. She stressed that she found it “completely unacceptable that such hybrid attacks” were being carried out with the use of people seeking to reach the EU, recalling that it was also a message she delivered to Russian President Vladimir Putin during a recent meeting. Poland, Lithuania, and Latvia have seen a rise in crossings by Iraqis, Afghans, Syrians, and Africans from Belarus in recent months. The three EU countries accuse Belarus of pushing the …