US President Barack Obama declared Tuesday that the United States and Europe will launch talks on what would be the world's largest free trade zone. "Tonight, I am announcing that we will launch talks on a comprehensive Transatlantic Trade and Investment Partnership with the European Union -- because trade that is free and fair across the Atlantic supports millions of good-paying American jobs," Obama said in his State of the Union speech. The move answered mounting calls from Europe to pursue a grand trade pact to spur growth on both sides of the Atlantic -- covering a region where two-way trade hit $646 billion last year.