By Leika Kihara and Promit Mukherjee

TOKYO/OTTAWA (Reuters) -Canada, chair of the Group of Seven advanced economies, is working with Japan and the European Union to maintain global stability in financial markets and the financial system, Canada's Ministry of Finance said on Wednesday, as many of the world's top finance leaders are on heightened alert for signs of deeper market upheaval following the Trump administration's tariffs blitz.

In a phone conference on Wednesday, Japanese Finance Minister Katsunobu Kato and his Canadian counterpart, Francois-Philippe Champagne, shared concerns over the series of tariffs implemented by the U.S. government, the ministry said in a statement.

Champagne also spoke to European Union Commissioner for Economy and Productivity Valdis Dombrovskis about impact and reactions to U.S. tariffs, a spokeswoman for the Canada Finance Ministry said.

Champagne has talked to his other G7 counterparts over the last few days regarding tariffs and restoring stability to the markets, the spokeswoman said.

U.S. President Donald Trump's sweeping tariff announcement on April 2 led to a market rout with bond prices tumbling and global stocks falling further. U.S. Treasuries, the safest haven for the global financial system, were hit by fresh selling pressure on Wednesday in a sign that investors were dumping their safest assets.

Trump later announced a 90-day pause on most tariffs but raised China's tariff rate, spurring a reversal in many markets.

Japan will cooperate with the G7 and the International Monetary Fund to help stabilize a market rout unleashed by U.S. tariffs, the country's top currency diplomat said on Wednesday.

Champagne welcomed the dialogue with Japan and emphasized the importance of the countries' existing trade relationship, Canada's finance ministry said in a statement. Canada is committed to continuing discussions, including as G7 President, on impact and reactions to U.S. tariffs, the statement said.

In past episodes of market upheaval, G7 finance chiefs have often collaborated on messaging and actions to soothe financial markets and ensure the smooth function of the financial system.

In the current instance, the market ructions have been caused by the G7 member with the biggest economic clout - the United States - and Trump administration officials have yet to signal serious concern about the violent swings in stock and bond markets following Trump's April 2 announcement of sweeping global tariffs.

"Within the G7 all of us outside the U.S. spoke to try to calm the situation and find a way to bring the Trump administration to the table and to a reasonable position," Italy's Economy Minister Giancarlo Giorgetti told reporters in Rome.

The White House and the Treasury Department did not reply to queries about the Japan-Canada statement.

When asked if the UK was part of the efforts proposed by Japan and Canada, British Finance Minister Rachel Reeves said its financial institutions, including the Bank of England, are in regular dialogue.

She said she was "absolutely certain" that this issue would feature in Washington later this month when G20 finance leaders gather on the sidelines of the International Monetary Fund spring meetings.