The rise of violent extremist ideologies among Commonwealth member states will be tackled by a new unit of experts partly funded by Britain, the prime minister will announce.

Britain will donate £1m a year for five years to the team whose focus will be on strengthening the ability of nations to counter extremist narratives.

Speaking before the Commonwealth heads of government meeting on Friday in Malta, David Cameron pledged to increase cooperation with the 53 member states of the Commonwealth to share best practice and identify new approaches to countering “poisonous ideologies”.

Cameron said: “The fight against extremism is something that affects us all. The Commonwealth has a vital role to play in broadening international efforts to counter extremism.

“Its civil society and education networks make it particularly well placed to complement international efforts to build counter-narratives to this poisonous extremist ideology. This is the struggle of our generation, but by working together we will defeat this extremist scourge that is a threat to us all.”

The Queen arrived in Malta before the Commonwealth heads of government meeting designed to tackle extremism. Photograph: Rex Shutterstock

A government source said a team of experts from various states would be seconded into a new unit in the Commonwealth secretariat – which manages the organisation – to work with civil society networks and governments. A particular focus will be states with a disproportionately high number of foreign fighters.

Cameron is also to announce £200,000 of seed funding to expand the recently established European counter-radicalisation youth network to include all Commonwealth countries. The youth network supports moderate youth voices in countering violent extremist messaging.

On Thursday the Queen, the Duke of Edinburgh, Prince Charles and the Duchess of Cornwall arrived in Malta amid a noticeably high security presence. Armed soldiers, including snipers, were posted on the roof of the airport as the Queen arrived and a convoy of military vehicles surrounded her plane as it landed.

The French president, François Hollande, will address the conference on Friday afternoon, which is set to be dominated by discussions over counter-extremism and the climate change summit due to start in Paris on Monday.