FOREIGN Minister Bob Carr says Sri Lankans are getting the message that economic migrants who arrive in Australian waters will be swiftly sent home.

"Every time we send a plane load back, a message goes out to the villages of Sri Lanka," he told Sky News on Thursday.

"You can pay what is, in Sri Lankan terms, a fortune to a people smuggler, but you will only be sent back, you won't get to make it to a new life in Australia."

More than 600 Sri Lankans asylum seekers have been returned involuntary since September.

"Sure that has cost a bit of money, but it has asserted Australian sovereignty and Australian control of irregular immigration," Senator Carr said.

The foreign minister leaves Australia on Thursday for visits to East Timor and Sri Lanka.

Originally published as Carr says Sri Lankans hearing message