TOKYO: Toyota battled Tuesday to seize back the initiative over a worldwide rash of safety recalls as the Japanese automaker, heading into a showdown in Congress, grappled with US criminal subpoenas.

Company president Akio Toyoda, who faces a grilling by US lawmakers Wednesday, admitted Toyota must do much better in responding to safety issues but pledged his commitment to "building the safest vehicles in the world".

The world's biggest carmaker, once a byword for quality, has recalled more than eight million vehicles over flawed accelerator and brake systems.

It faces a host of US class-action lawsuits potentially costing billions of dollars that link its defects to more than 30 deaths.

The company revealed Monday it had been subpoenaed in a US criminal investigation of its handling of the mass recalls, and had received a similar demand for documents from the Securities and Exchange Commission.

Writing in the Wall Street Journal, a contrite Toyoda said: "I recognize that we must do better -- much better -- in responding to safety issues."

He said that "it is clear to me that in recent years we didn't listen as carefully as we should -- or respond as quickly as we must -- to our customers' concerns".

Toyoda, who assumed his post last June, pledged to take the company "back to basics" and vowed that "Toyota will set a new standard for transparency and speed of response on safety issues".

The 53-year-old grandson of the company's founder added: "All Toyota vehicles bear my name. When cars are damaged, it is as though I am as well." Related article: Toyota must do better: president

Critics have attacked Toyota for its sluggish response to complaints of sudden, unintended acceleration and accused it of covering up defects, which also extend to the brake systems of its iconic Prius hybrid cars.

Former US Toyota lawyer Dimitrios Biller, now embroiled in a legal battle with the company, has accused it of hiding and destroying evidence of safety flaws and of propagating "a culture of hypocrisy and deception".

One US House of Representatives committee was due to question Toyota Motor Sales USA president Jim Lentz on Tuesday about the firm's handling of the defects.

"Toyota's public statements about the adequacy of its recent recalls appear to be misleading," wrote Bart Stupak, the Michigan Democrat who chairs the House Subcommittee on Oversight and Investigations.

Company chief Toyoda will face questioning Wednesday before the House Oversight and Government Reform Committee, whose senior Republican is California Representative Darrell Issa.

"If you haven't done anything wrong, then you have nothing to hide, and there is no reason why Toyota should not be able to provide straightforward and honest testimony," Issa said.

In the Wall Street Journal, Toyoda said the company was addressing safety concerns by expanding its US field monitoring team.

It has asked an outside engineering consultancy to analyse its electronic throttle control system -- which connects the gas pedal and engine electronically, not mechanically -- and make its findings public.

Toyota has said the system is not the cause of the defect that has caused some cars to race dangerously out of control.

The company chief reiterated that Toyota will fit all new vehicles with a brake-override system, which cuts engine power when the brake and accelerator pedals are pushed at the same time.

Toyoda, who initially turned down an invitation to appear in Congress, said he welcomed the opportunity to address the House committee Wednesday.

"I look forward to speaking directly to Congress and the American people tomorrow about the decisive actions Toyota is taking to make things right for our customers by building the safest vehicles in the world."