Tokyo ? As pressure intensifies for Toyota’s chief to testify before Congress about the automaker’s safety lapses, Japanese political leaders and experts worry that the problem — if handled poorly — could damage ties between the two nations.

Relations between Washington and Tokyo are already strained by a dispute between the two governments over the relocation of a key U.S. Marine base on the southern island of Okinawa.

Political tension rose a notch Thursday when a Republican in the House of Representatives said he would support issuing a subpoena to compel Toyota President Akio Toyoda to appear before congressional committees later this month to examine the company’s string of safety problems.

Toyota said Toyoda is expected to visit the U.S. in early March, but the company declined to confirm Japanese media reports that he would attend the Washington hearings. Toyota’s North American head, Yoshimi Inaba, will appear before the committees, the company said.

Even before the world’s biggest automaker announced its latest recall Tuesday of nearly 440,000 Prius and other hybrids, bringing its global total to 8.5 million vehicles for faulty gas pedals and brakes, Foreign Minister Katsuya Okada expressed concern about that the problem could become a political headache.

Further underscoring Toyota’s woes, the automaker said Friday it is recalling about 8,000 Tacoma pickup trucks from the 2010 model year to fix a problem with the front propeller shaft that could cause the vehicle to lose control.

“I’m worried,” Okada said last Friday. “It’s not just the problem of one company but a diplomatic issue,” noting that the fiasco comes at a particularly difficult time for the automobile industry, including General Motors Corp.’s bankruptcy filing.

Japan has also been criticized for its tax incentive program for “green” cars that Washington said unfairly excluded American vehicles. The program has since been expanded to include more U.S. cars.

So far, there’s no sign that Toyota’s recall has become a contentious issue between the Obama administration and the Tokyo government.

But it could become prickly if the hearings in Washington go badly — if, for example, Toyota executives come across as aloof or U.S. politicians come down in a way perceived in Japan as excessively harsh.

To demonstrate responsibility, Toyoda himself needs to appear before the congressional committees, experts say. He also plays a key role as the representative of Japan Inc.’s flagship company.

“The final authority needs to be there and explain the situation and say what the company is doing to resolve the problems,” said Yamamoto.

Economy and trade minister Masayuki Naoshima urged Toyoda to at least make a public appearance in the United States — Toyota’s biggest market.