Japan's transport ministry may reform its car recall system, reports said today, as Toyota faces accusations of delays over drivers' complaints.

The step reflects deepening concerns in Japan over Toyota's recalls of more than eight million vehicles, most of them in overseas markets.

Transport minister Seiji Maehara told Japanese MPs on Friday that he hoped to try to improve his agency's recall system to respond better to consumer interests, Kyodo News agency said.

"We will consider reviewing the recall system to make it more familiar to users," Mr Maehara told a lower house committee.

The agency may require car makers to move more quickly to fix defects and may expand the types of problems subject to reporting requirements, according to the reports. The reports cited unnamed ministry officials.

Toyota's president Akio Toyoda is to appear before the US House of Representatives Oversight and Government Reform Committee on Wednesday. Its chairman, Rep Edolphus Towns, a Democrat from New York, virtually compelled Toyoda to attend last week after issuing a formal invitation for him to testify.

Toyota has not given any details of Mr Toyoda's travel plans, though the Japanese newspapers Yomiuri Shimbun and Mainichi Shimbun reported he left Japan over the weekend.

Mr Maehara and other Japanese officials have praised Mr Toyoda's decision to attend the hearing, saying he should use the opportunity to reassure customers angered by recalls over sticking accelerator pedals, accelerators jamming in floor mats and momentarily unresponsive brakes.

US safety regulators are also investigating complaints about power steering in the Corolla, Toyota's top-selling model worldwide, with 1.3 million sold last year. The estimated 500,000 Corollas in question in the US market are not made or sold in Japan.

But there has been relatively little talk in Japan about how and why its famously impeccable quality control regime failed - and in mainly overseas markets.

But a review by the transport ministry could focus on such issues inside Japan, where the company has recalled about 223,000 Prius hybrid cars for braking problems.

The number of complaints over quality and safety issues in the US has dwarfed those in Japan, largely because the millions of Toyota vehicles subject to recalls were made with parts not used in models made and sold in Japan.

The recalls crisis has raised doubts over the Japanese car maker's sterling reputation, earned over decades of striving to win over American and European drivers.

Even Mr Toyoda, grandson of the company's founder, has publicly lamented the difficulties of keeping a grip on quality in an era of outsourcing and global expansion.

"We so aggressively pursued numbers that we were unable to keep up with training staff to oversee quality," he told reporters at a news conference in Tokyo last week.

Mr Toyoda has promised an outside review of company operations, better responses to customer complaints and improved communication with the US government.

Japan, where the customer is said to be "king", has had plenty of product quality crises - some of the most notorious involving cars and the transport ministry keeps public records of recalls and drivers' complaints.

But Japanese citizens tend to be less assertive, partly because the legal system and other government institutions are more likely to side with manufacturers than with consumers.