May 29th is the International Day of United Nations Peacekeepers. The day was designated in 2002 to pay tribute to those men and women who have served with the UN to keep international peace and security. Secretary-General Antonio Guterres is heading to Mali to meet the country's Blue Helmets -- who serve at the deadliest UN mission in the world. Our UN correspondent Liling Tan has more on what to expect.

LILING TAN NEW YORK "On Tuesday, May 29th, the International Day of UN Peacekeepers, the Secretary General will be in the Malian capital of Bamako, to meet with members of the UN mission there known as MINUSMA. There, he will pay tribute to the 42 peacekeepers and personnel killed in action at this UN mission that has suffered the greatest loss in 2017, for the fourth straight year. Here's part of the UN Chief's message ahead of the visit."

ANTONIO GUTERRES UN SECRETARY GENERAL "This year, I will spend the International Day of United Nations Peacekeepers in Mali to express my solidarity with colleagues facing high casualties and enormous volatility. As we recognize a legacy of service and sacrifice around the world, I am also committed to taking action for peacekeeping - action to make our operations safer and more effective in today's challenging environments."

LILING TAN NEW YORK "The Secretary General also repeated his promise to promote human rights and address sexual exploitation and abuse, which has long plagued UN peacekeeping operations. He will be accompanied by peacekeeping chief Jean-Pierre Lacroix, Under-Secretary-General for Field Support Atul Khare, and head of UNICEF Henrietta Fore. He will also meet with the Malian President and Prime Minister. The occasion will also allow the UN chief and his agency to thank more than one million men and women who have served under the UN flag, including those currently serving in 14 missions across four continents. More than 3,700 peacekeepers and UN mission personnel have died in service since the UN's first mission was authorized on May 29th, 1948. And when the Secretary General returns to New York later in the week, he will officiate at a wreath-laying ceremony here to honor fallen peacekeepers. Liling Tan, CGTN, New York."