* Protectionism on agenda at G7
* Trump has rattled allies with steel tariffs aimed at China
* Japan's exports could falter if protectionism spreads (Adds quotes, details on trade friction)
By Stanley White
TOKYO, June 6 (Reuters) - Japanese Prime Minister Shinzo Abe said on Wednesday that he wants to send a message at a Group of Seven leaders' summit that no countries benefit from trade protectionism.
The G7 leaders summit to be held June 8-9 could turn into a tense encounter after frustration with U.S. tariffs on steel and aluminium spilled into the open at a G7 finance ministers' meeting last week.
"No country benefits from retaliatory trade restrictions," Abe told reporters.
"My message is G7 should play a role in free and fair global economic development," he added.
Abe also said the G7 should send a message that it supports U.S. President Donald Trump as he prepares for a summit meeting with North Korean leader Kim Jung Un in Singapore.
Trump, who is due to attend the G7 leaders' meeting in the Canadian province of Quebec, imposed tariffs last week of 25 percent on steel and 10 percent on aluminium from Canada, the European Union and Mexico, citing national security reasons.
G7 finance ministers met last week and rebuked Washington over the tariffs, setting up a fight at the G7 leaders' summit.
In a rare show of division among the normally harmonious club of wealthy nations, the six other G7 member countries issued a statement asking U.S. Treasury Secretary Steven Mnuchin to convey their "unanimous concern and disappointment" with the tariffs.
All six of the other G7 countries - Britain, Canada, France, Germany, Italy and Japan - are now paying the metals tariffs, which are largely aimed at curbing excess production in China.
Canada and Mexico, which are embroiled in talks with the United States to update the North American Free Trade Agreement, responded to the move by announcing levies of their own on a variety of U.S. exports.
The EU is also set to retaliate with tariffs on a range of U.S. goods, from Harley-Davidson motorcycles to jeans and bourbon.
Trade protectionism poses risks to Japan's economy partly because many of its companies in electronic parts, semiconductors and chemicals ship goods to China, where they are used to make final products destined for the United States and other markets.
Declines in household spending and industrial output have raised concerns that Japan's domestic demand has stalled after two consecutive years of brisk growth.
If Japan's exports also weakened due to trade protectionism that would be a double blow to the country's outlook for growth. (Reporting by Stanley White Editing by Chris Gallagher and Darren Schuettler)