Prime Minister Pierre Trudeau, who sits down with President Reagan in Washington Thursday, will spell out the Canadian view forcefully on acid rain and Mr. Trudeau's recent peace initiative, say his advisers.
Canada and the United States, while essentially friendly neighbors who share a largely unguarded 5,000-mile border, have an uneasy edge to their relations.
Controversies like that swirling around acid rain loom large here. Most Canadians, according to opinion polls, feel that Washington is dragging its heels on finding a solution to the acid rain problem.
Trudeau is also expected to present the message of his quest for world peace. Among his proposals are a call for a summit of the five major nuclear powers and an offer to serve as a mediator between East and West.
He announced the initiative in October. Since then, he has visited China and Western Europe. The concept was hailed in France, West Germany, and the Vatican, while China and Britain have been less enthusiastic. He is now seeking Mr. Reagan's blessing for the effort.
Although Trudeau's peace initiative has not received the attention many Canadians thought it should, particularly in the US, his advisers believe support is growing. They hope Reagan will give it a favorable nudge.
As with the acid rain controversy, there is considerable Canadian pique over US failure to treat the Trudeau initiative seriously.
''This is another clear example,'' complained the Winnipeg Free Press, ''of Washington's insensitivity to Canada and Canadians.''
For Canadians, there is irony in all this. After all, they note, Canada is the US's largest trading partner. In 1982, Canadians purchased $33.7 billion of US goods.
''Isn't it time for the United States to stop taking Canada for granted?'' says a Trudeau associate. ''Because we are allies and do not cause the United States the problems of the Middle East or Central America, there's a tendency in Washington to ignore our views. But we are involved in the fate of the world.''
Underlying the Canadian pique is the feeling here that not only is the Reagan administration ignoring the Trudeau peace effort, but also that it is taking the US - and an unwilling Canada as well - toward deeper involvement in Mideast and Central American conflicts.
Many Canadians have a somewhat cynical view of the Reagan administration's commitment to peace. They feel that each escalation of Mideast tension gets the US closer to a shooting war that will drag Canada along as well. Canadians are concerned that when push comes to shove, Reagan ''will shoot from the hip rather than wait and pursue peace,'' a Montreal radio commentator said.
Last week an editorial cartoon in the Toronto Star summed up this Canadian concern. The cartoon shows Reagan about to board a helicopter, saying: ''I want you to know the crisis situation in the Middle East is nothing to be alarmed about and I assure you I'll be monitoring it closely from my bunker in Colorado.''
Canadians clearly support the Trudeau peace initiative. They hope Reagan will not think Trudeau's decline in political popularity at home indicates a lack of interest in his method of seeking global peace.
The same could be said for his efforts to get a joint Canada-US attack on acid rain. To most Canadians, this issue is every bit as important as the peace quest.
They were enthusiastic in late November when the US and Canada agreed to set up a commission to try to resolve Canadian concerns over dam construction in North Dakota. In October, Canada sent a protest to the US, citing potential ecological dangers of constructing a reservoir in an area that lies between the watersheds of two river systems (the Missouri-Mississippi rivers and the Hudson Bay drainage system).
In Manitoba, which lies just north of North Dakota, the project has become highly political. But the issue has attracted attention throughout Canada and added fuel to the overall Canadian concern on ecological issues which dominates current Canada-US controversies.