I was married to a western woman and I have two children with her. Do I have responsibility to visit these children now?
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
The Prophet said: “All of you are guardians and are responsible for the people under your guardianship.” [Al-Bukhari and Muslim]
Therefore, you have to visit your children and take care of them. Also, you have to raise them according to Islam and put the love of Allah and His Prophet in their hearts.
Know that if their mother is non-Muslim, she does not have the right of raising them. So, you should not leave your children with her since this affects their religion. The Prophet said: “Every child is born on the Fitrah (natural predisposition upon which Allah created mankind – i.e. Islam) and then his parents make him a Jew, a Christian or a Magian.” [Al-Bukhari and Muslim]
Allah knows best.
You can search for fatwa through many choices