The most important issue is that your friend can be honest with you about how they feel. Even if you are not used to dealing with such situations, and if you feel frightened or upset, it is important to offer support for the fact that your friend is being honest with you. It is also very important to reassure your friend that you understand how badly they must feel to have thoughts of suicide, but to insist that there are other solutions to the situation. Your friend may insist the pain and emotional distress of their problem will never pass, but people survive war, and even the painful memories of wars eventually fade away. Human beings are programmed to survive and to overcome and forget pain in time.
Remember that if someone is talking to you about suicide they are still considering not taking their own life. They are seeking help.