Narrated Al-Bara (radiallaahu `anhu):
The Prophet (sallallaahu `alayhi wasallam) assumed Ihram for Umra in the month of Dhul-Qa'da but the (pagan) people of Mecca refused to admit him into Mecca till he agreed on the condition that he would not bring into Mecca any arms but sheathed.
Prophet (sallallaahu `alayhi wasallam) agreed to the condition put forward by the pagans in order to be able to do `Umrah. It makes sense that he did that since the Quraysh were the custodians of Ka`bah at that time, so they had the authority.
Nowadays, the Saudi government is responsible for the pilgrims, so if they put forward any terms and conditions for those who intend to perform Hajj/`Umrah, the latter should comply. :)