Hong Kong will spare no effort in fighting international terrorism, Secretary for Security Ambrose Lee says, adding one of his challenges is to maintain the integrity and effectiveness of Hong Kong's immigration and customs control, while maximising convenience in the movement of people and goods.

Speaking at a lunch gathering hosted by the Hong Kong Association in London today, Mr Lee said as the word's busiest container port, Hong Kong was quick to answer the US' Container Security Initiative.

"We have also worked closely with organisations such as the International Civil Aviation Organisation and the International Maritime Organisation in implementing security and safety measures," he said.

Mr Lee said Hong Kong witnesses 350,000 passenger and 31,000 vehicular crossings in both directions daily at its boundary control points with the Mainland.

"Ensuring such traffic is dealt with in an efficient manner and yet maintaining security integrity is a real challenge. This is particularly so when trade facilitation and market access are equally important parameters in the equation," he said.

Given Hong Kong's strategic location, Mr Lee said Hong Kong is also watchful of passenger and cargo flow through the city to other destinations.

"Obviously we cannot single-handedly manage this task. Again the sharing of intelligence and co-operation with our partners is vital in our management of the risks," he said.