TOKYO (Reuters) - Japanese carmaker shares have underperformed their peers in the United States so far this year as investors fret over U.S. President Donald Trump’s protectionist stance, ahead of his meeting with Prime Minister Shinzo Abe later in the day.

Newly manufactured cars await export at a port in Yokohama, Japan, January 16, 2017. Picture taken January 16, 2017. REUTERS/Toru Hanai

With Trump branding Japan’s auto trade as “unfair” and accusing Tokyo of using monetary policy to devalue its currency to boost exports, Japanese car makers are seen as likely to take the brunt of any flare-up in trade friction between the two countries.

The Tokyo Stock Exchange's transport equipment makers index .ITEQP.T, which largely consists of car makers, has fallen 2.3 percent so far this year, with Mazda Motor Corp 7261.T falling 16.9 percent and Toyota Motor Corp 7203.T 6.3 percent.

That compared with gains of 1.4 percent in the Nikkei average share price index .N225.

“It is hard to buy the sector with mid/long-term uncertainties,” said Ryoma Sugihara, director of equity sales at Societe Generale Securities.

Japanese automaker shares fared worse than their U.S. competitors even as Trump bashed U.S. car makers for having production operations in Mexico.

The hit stems from fear that Trump’s “America First” policies might put Japanese firms in difficult positions.

“There are expectations that U.S. auto shares would perform better than their overseas counterparts, as Trump is putting pressure on Japanese and European automakers,” an analyst at a Japanese securities firm said.

General Motors Co GM.N has risen 0.7 percent, while Ford Motor Co F.N has gained 2.1 percent. Fiat Chrysler Automobiles NV FCAU.K has soared 18.5 percent.

Trade experts note, however, that World Trade Organization (WTO) rules should give Japan some protection, unlike in the 1980s when Japan agreed to voluntarily curb car exports to the United States.

“Given the rules and procedures by the WTO, it would be difficult to impose measures similar to those taken during the 1980s, as long as the U.S. remains a WTO member,” said Hiroshi Mukunoki, professor of economics at Gakushuin University in Tokyo.

After a trade war in the 1980-90s, Japanese car makers expanded U.S. production and their U.S.-bound exports declined to 1.73 million vehicles in 2016 from 3.13 million in 1985.

Still, last year Japan earned $39.3 billion through car exports, which accounts for a large part of its $68.9 billion trade surplus with the United States. In contrast, U.S. car exports to Japan amounted to only $0.5 billion.

Trump’s meeting with Abe comes just a few days after U.S. data showed Japan became the second-largest contributor to the U.S. trade deficit after China, with automobiles accounting for a bulk of it.

“This data came at a really bad time. Trump may demand measures to help slash the (U.S.) trade deficit,” said Nobuyuki Fujimoto, senior market analyst at SBI Securities.