The prime ministers of Singapore and Australia say China should not see increased military cooperation between their countries through a bilateral deal that will dramatically expand northern Australian training facilities as an attempt to contain Beijing.

Australian and Singaporean officials on Thursday signed a pact under which Singapore will spend up to 2.25 billion Australian dollars ($1.7 billion) to double the capacity of its facilities in military training areas in Queensland state.

Singapore's Prime Minister Lee Hsien Loong told reporters he does not think "Singapore and Australia together could possibly be seen as a block" to China.

Australian Prime Minister Malcolm Turnbull says he agrees with Lee.

The Chinese embassy in Australia did not immediately respond to a request for comment.