Travellers are being warned that an upcoming strike by members of the Australian Border Force and Department of Immigration could delay international travel.

The Community and Public Sector Union (CPSU) has announced members will walk off the job for 24 hours on August 12, to protest a protracted dispute with the Federal Government over pay and conditions.

It is the first strike since the Federal Government won a Fair Work Commission ruling preventing industrial action for three months, on the basis that terrorists or criminals could exploit depleted staff numbers during a strike.

The ruling came a month after the union chose to delay strike action in the wake of the Brussels airport bombing.

The CPSU warned the action could cause delays at international airports, however CPSU national secretary Nadine Flood said staff working in intelligence and counter-terrorism would not be affected.

"Despite Border Force's cynical tactics in the Fair Work Commission prior to the election, our members are 100 per cent committed to national security and their action will not compromise the safety of passengers in any way," she said.

The union has been locked in a pay dispute with the Federal Government for more than two years, and Ms Flood said the union had written to Prime Minister Malcolm Turnbull, calling for an urgent meeting to end the impasse.

"Prime Minister Turnbull can avert future strike action, including the prospect of broader industrial action across the Commonwealth public sector, by working with us to fix this mess," she said.

Other departments, including quarantine and biosecurity, are also scheduled to hold stop-work meetings on August 12.