The Group of 20 countries vowed Saturday at their summit to tackle "unilateral trade measures inconsistent" with World Trade Organization rules, in an apparent challenge to the tariffs imposed by U.S. President Donald Trump, who is not attending the meeting.With Trump absent and the United States not sending any government officials, the summit took the unusual step of adopting its leaders' declaration at the outset of the meeting. It was then unveiled by South Africa, this year's G20 host.Trump has repeatedly snubbed the framework as he pursues his "America First" mantra, upending multilat…READ FULL ARTICLE