How to back up files from iphone without connecting to the internet?

I can't connect my iphone to the computer nor to itunes but I need to back up the files, I tried using icloud but it doesn't have enough memory to save it. Are there any ways?

Follow up with these tips to backup files from the iPhone
1. Go to Settings
2. You would now see Personal, Backup and reset options
3. Select both Backup my data and Automatic restore.
4. You have your backup phone