The US government stops new people from coming into the country. This is because a soldier died in Washington DC. A man from another country hurt two soldiers. One soldier died.
Now, the US will not say "yes" or "no" to people who want to live in America for safety. This is a big change. The government wants to check everyone very carefully first.
The US also will not give papers to people from Afghanistan to visit. The government says keeping Americans safe is the most important job.
Many people are waiting and do not know what will happen. Some people think this new rule is not good.