Once you are in the United States, you are allowed to apply for asylum, it doesn’t matter about your country of nationality (home country) and asylum is not affected by your current immigration status.
You have to prove that you were persecuted or have a fear that you will be persecuted in your home country. There are only a few categories or reasons that you can say caused this persecution. These are because of your race, nationality, religion, membership in a particular social group, or political opinion. You can fall into more than one category but you must have some evidence to help convince the interviewer about the truth of what you say.
Make sure that when you are seeking asylum you remember that: You MUST be physically present in the United States for less than one year from the date of your last arrival. You can show that you were persecuted or that you are afraid you might be persecuted because of your race, religion, nationality, political opinion or membership in a particular social group.
Also, you can include your spouse and all of your unmarried children who are under the age of 21 years old on your application when you submit it.
Documents can help to prove your asylum case. Get letters, affidavits, medical records, newspaper clippings that help your case. Remember you have to show that you were persecuted or fear persecution.