One of the parties must have an internet connection though. You can generate and sign a transaction without internet access, much as you would do on an airgapped machine, and you can send that signed transaction to another party any way you like - via telephone call, radio waves, TxTenna, snail mail, even carrier pigeon if you were so inclined. But until the receiving party broadcasts that transaction to the network via the internet, then that transaction doesn't exist on the blockchain, and so the bitcoin hasn't been sent anywhere. Someone must have internet access at some point to broadcast the transaction. And until the transaction is broadcast, the sender could easily double spend by establishing internet access and broadcasting a different transaction in the meantime.