Okay kiddo, so China is a country that has a lot of people living in it, just like how your school has a lot of kids. And just like how some kids might bring toys to school that can be dangerous, China has some things called "weapons of mass destruction" that can be very dangerous too.
These weapons of mass destruction include things like nuclear bombs, which are super powerful and can make a big boom that can hurt a lot of people. China has said that they don't want to use these weapons unless they really have to, kind of like how you wouldn't want to hit someone with a toy unless it was an emergency.
But the scary thing is that not everyone in the world trusts China not to use these weapons, or to use them responsibly. Some other countries have these weapons too, and they all agreed to try to make as few of them as possible so that they could be safe. But some people worry that China might be making more of these weapons than they're supposed to, or that they might not be using them safely.
So sometimes the leaders of different countries talk to each other to try to figure out ways to make sure no one gets hurt by these dangerous weapons. It's kind of like when your teacher talks to you and your classmates to make sure no one is hurting each other with toys. It's important to be safe and not hurt anyone, especially when it comes to things as serious as weapons of mass destruction.