Australia has given more than $1 million of weapons and equipment to Solomon Islands police, as part of a push to strengthen the force.
The donation by federal police to the Pacific nation included 60 MK18 rifles and 13 vehicles, along with specialist training to officers.
Four of the vehicles will be used to help set up a mobile protection unit for Solomons police, which will manage security threats to critical infrastructure.
The $1.3 million gift by Australia was made as part of a partnership program between the two countries, and will help boost the capability of Solomons police in the lead up to next year's Pacific Games.
However, the donation has been slammed by the country's opposition leader Matthew Wale, who said it was "very disturbing".
Mr Wale questioned whether the weapons would be used by police to stop unrest.
"Obviously we do not have external threats so why the introduction of these high-powered guns? Or are we on the pathway of being militarised again?" he said in a statement on social media.
"It is clear Australia is anxious that if they do not supply guns then China will. Geopolitical interests have surpassed national interest in this country and it is a sad state of affairs."
The donation of equipment follows high tensions in the Indo-Pacific after the Solomons' decision to sign a security pact with China.
Concerns were raised that the deal could lead to military bases being established by China in the Solomon Islands, claims both nations have rejected.
China has also attempted to ink similar security deals with other Pacific nations.
Federal police said the rifles donated to the Solomons were part of a "rearmament program", saying it would be used to maintain peace and stability.
Australian Federal Police acting commander Clinton Smith said Australia was committed to giving the Solomon Islands forces the best possible resources.
"The AFP is proud to be the Solomon Islands' security partner of choice and will continue to work closely with (Solomon Islands police) officers to ensure they are trained and equipped to provide the Solomon Islands community with an efficient, modern police force," he said.
"The AFP and (Solomon Islands police) have a deep friendship that is regularly demonstrated through the sharing of resources and capability to ensure current and future security challenges and needs in the region are met."