U.S. President Donald has extended a periodin which some countries will not pay import taxes,or tariffs, on some products.His administration says it is giving trade negotiators30 more days to work out a deal.The exemptions were to have ended on Tuesday May 1.The tariffs have already been put into effect on China and Russia.But the European Union (EU), Canada and Mexico received exemptionsfrom tariffs on their aluminum and steel exports to the U.S.The European Commission criticized the temporary extension in a statement Tuesday.The group said the EU has been willing to discuss the issueand "will not negotiate under threat."The commission said, "The U.S. decision prolongs market uncertainty,which is already affecting business decisions."It added that the tariffs, which are meant to protect U.S. industry,cannot be justified by national security concerns.German Chancellor Angela Merkel spoke to Trump last weekduring a visit to the White House.She warned that trade relations between the alliescould worsen if the EU does not receive a permanent exemption.On Monday, Canadian Prime Minister Justin Trudeauwarned against placing tariffs on his country's steel and aluminum.He said such measures could hurt the U.S. car and aerospace industries,which depend on imported materials.Late Monday, the U.S. announced that it had reached a final deal with South Korea,which will receive a permanent exemption from the tariffs.It said that early agreements had been reached with Argentina, Australia and Brazil.The Trump administration has saidthat some countries sell their steel and aluminum at unfairly low prices.And President Donald Trump has said this competitionhurts U.S. industries that are important to national security.The U.S. has placed a 25 percent tax on many steel importsand a 10 percent tax on aluminum as a result.