Praise be to Allah.
Hajj is one of the pillars of Islam. Whoever denies it or resents it after the proof has come to him is a kaafir. He should be asked to repent; if he repents, all well and good, otherwise he should be executed. The one who is able to do it should hasten to perform the duty of Hajj, because Allaah says (interpretation of the meaning):
“And Hajj (pilgrimage to Makkah) to the House (Ka‘bah) is a duty that mankind owes to Allaah, those who can afford the expenses (for one’s conveyance, provision and residence); and whoever disbelieves [i.e. denies Hajj (pilgrimage to Makkah), then he is a disbeliever of Allaah], then Allaah stands not in need of any of the ‘Aalameen (mankind, jinn and all that exists)”
[Aal ‘Imraan 3:97]
And Allaah is the Source of strength.