President Donald Trump sounded open Tuesday to the possibility of an inter-Korean dialogue after North Korean leader Kim Jong Un made a rare overture toward South Korea in a New Year's address. But Trump's ambassador to the United Nations insisted talks would not be meaningful unless the North was getting rid of its nuclear weapons. In a morning tweet, Trump said the U.S.-led campaign of sanctions and other pressure were beginning to have a "big impact" on North Korea. He referred to the recent, dramatic...