We've been reporting on a proposed summit between the leaders of the United States and North Korea.It would be historic if it happens, sitting leaders from these two countries have never met face to face before.But it's an on-again/off-again event. And now, it appears to be on again.U.S. officials have been meeting with North Korean officials at the demilitarized zone, the border between North and South Korea.And one of the communist country's highest ranking members is set to meet with the U.S. secretary of state in New York this week.The summit between U.S. President Donald Trump and North Korean leader Kim Jong-un had originally been scheduled for June 12th in the Asian island country of Singapore.But President Trump cancelled it last week in a letter to Kim,after North Korea had threatened a nuclear showdown with the U.S.American officials also said the North Koreans had not been showing up to planning meetings for the summit.So, what's changed since then?The White House says after the letter was sent, the North Koreans have been communicating again,and the president's recent tweets have indicated that the summit is back on track.It still looks like it will be in Singapore. There are still some questions about when though.A White House official says Americans lost a week of planning and that June 12th maybe too soon. But things seemed to be moving forward.Next today, another search has ended, but a tragic mystery goes on.What happened to Malaysia Airlines Flight 370?We've been following this story since 2014, when the flight from Kuala Lumpur, Malaysia, to Beijing, China, vanished. There were 239 people on board.