Jan 21 (Reuters) - U.S. President Donald Trump on Wednesday withdrew a threat to impose tariffs on a number of nations for their stance on Greenland, saying he had reached the outlines of a ​deal with NATO on the island's future. "Based upon this understanding, I will not be imposing the tariffs ‌that were scheduled to go into effect on February 1st," Trump wrote on Truth Social after a meeting with NATO Secretary General Mark Rutte ‌in Davos. He did not give details of the deal. MARKET REACTION *U.S. ...