Finance ministers and central bankers of the world’s 20 biggest economies have rejected protectionism and urged “further dialogue” on trade. However, they failed on Tuesday to defuse the threat of a trade war days before US metals tariffs take effect and Washington is to announce measures against China. The G20 financial leaders discussed trade disruptions as a risk to growth at a two-day meeting in Buenos Aires. They agreed only to stand by an ambiguous declaration on trade from 2017 and “recognize” the need for more “dialogue and actions,” Reuters reports. Their declaration did little to dispel concern over a global trade war as the United States’ tariffs of 25 percent on imported steel and 10 percent on aluminum take effect on Friday.