You can start with this website http://nigeria.usembassy.gov/ A letter of invitation is usually advised. They may also need to show strong ties to their country, such as family, a job, home, a bank account.
Quick Answer. Over one billion Muslims live in Asia, which makes it the continent with the highest Muslim population. Indonesia is the country with the largest Muslim population, with 209 million people. Continue Reading.
Around 62% of the world's Muslims live in the Asia-Pacific region (from Turkey to Indonesia), with over 1 billion adherents. The largest Muslim population in a country is in Indonesia, a nation home to 12.7% of the world's Muslims, followed by Pakistan (11.0%), and India (10.9%).