WASHINGTON, Oct. 4, 2018 (Xinhua) -- U.S. National Security Adviser John Bolton speaks at a White House press briefing in Washington D.C., the United States, Oct. 3, 2018. U.S. National Security Adviser John Bolton said here on Wednesday that the United States is withdrawing from the Optional Protocol to the Vienna Convention on dispute resolution. (Xinhua/Ting Shen/IANS) by .