VANCOUVER - Prime Minister Justin Trudeau will personally reveal today what Canada has offered to provide the United Nations in terms of troops and military equipment for peacekeeping missions.

The moment will mark Canada's first tangible step back into peacekeeping since the Liberals promised last year to provide the UN with up to 600 troops and 150 police officers.

But like that commitment, which stopped short of committing to any specific mission, Trudeau's announcement is also expected to be missing some key details.

Sources say the government has put several offers on the table for the UN's consideration, including the deployment of helicopters to help in Mali, and a transport plane in Uganda to assist different missions in Africa.

It is also reportedly ready to provide a rapid-reaction force in the Golan Heights between Israel and Syria; assist the UN's new police mission in Haiti; and send trainers to help other countries get better at peacekeeping.

But UN and Canadian officials are said to still be hammering out many of the details, such as when and how those offers would be employed.

Trudeau's decision to personal reveal Canada's offer during this week's peacekeeping summit in Vancouver nonetheless sends a message that the government is intent on delivering on its promise to help the UN.

The prime minister's announcement will be one of a number of highlights during Wednesday's meeting, which is being attended by representatives from 80 countries involved in peacekeeping.

Retired lieutenant-general Romeo Dallaire will help roll out a new set of commitments for the international community to sign onto aimed at preventing the use of child soldiers and better protecting children in conflict.

The UN released a report last month that found more than 8,000 children were killed or injured in conflicts around the world in 2016 and thousands of children had been recruited or used by warring factions.

Academy Award-winning actress Angelina Jolie is also scheduled to deliver a keynote address on preventing and better addressing sexual violence in armed conflict.

After long ignoring the issue of sexual violence in war, the international community has in recent years stepped up its efforts to end rape and other sexual crimes in conflict zones and to hold perpetrators to account.

But the UN has also struggled with revelations that peacekeepers themselves have either sexually abused or exploited the very people they were meant to protect in a number of countries.

Defence Minister Harjit Sajjan kicked off the two-day Vancouver summit on Tuesday by noting that not only did Canada help invent peacekeeping, but 120,000 Canadians have worn blue helmets or berets over the years.

Yet Sajjan also reminded delegates, including foreign dignitaries, military officials and civil society actors, that peacekeeping has changed since Canada was among the top troop-contributing countries in the 1990s.

And he said it is imperative that the international community adapt to ensure the UN can respond effectively in what are increasingly complex and dangerous environments and conflicts.

"Today, it's rare to see UN peacekeepers monitoring a ceasefire between two countries. Today's missions are often undertaken in areas of ongoing conflict. Places where there is not much peace to keep," he said.

"It's more about protecting civilians and working to build a peace in a hostile environment where belligerents are not identified. In the face of this extraordinary and evolving challenge, we must ask ourselves: What can we do better? What must we do differently?"