PM disappointed by Vietnam cancellation

Malcolm Turnbull says Vietnam has shown disregard for veterans over its decision to not permit the 50th anniversary commemorations of the Battle of Long Tan to proceed.

The prime minister says he's deeply disappointed at the Vietnamese government's decision and will seek a telephone call with his counterpart.

"This decision and especially its timing shows a disregard for those Australians who have in good faith travelled to Vietnam to participate in this week's events," he told a Long Tan dinner in Canberra on Wednesday.