The National Highway Traffic Safety Administration said it requested that Toyota, which owns the Lexus luxury brand, recall model year 2010 Lexus RX 350 and RX 450 H vehicles "for a serious safety issue involving potential pedal entrapment by the floor mat."
If the mat traps the gas pedal, the vehicle could speed out of control.
On Friday, Toyota said it was launching the recall, which affects 154,000 vehicles.
Safety regulators also warned the automaker that it might face another investigation as to whether the company "met its obligation to notify the agency and conduct a recall in a timely manner." Previously, Toyota paid record federal fines of nearly $50 million for failing to promptly inform regulators of defects in its vehicles and for delaying recalls.
The latest safety administration move follows a massive Toyota recall of 4.4 million vehicles sold in the United States in late 2009 to resolve concerns that floor mats in cars and trucks could cause gas pedals to become stuck, leading to uncontrollable acceleration.
That recall was later expanded to cover 14 models of Toyota and Lexus vehicles, including various years of Camrys, Priuses and Tundra pickups, but not the RX model of SUVs.
"In our view, the data available at the time didn't warrant the inclusion of this model," Toyota spokesman Brian Lyons said Friday. "If NHTSA decides to open an investigation, we'll certainly cooperate with its efforts."
Lyons noted that of the 6.9 million Toyota vehicles that had been recalled for problematic floor mats before Friday, 85% had been brought back and fixed.
The original recall came after a San Diego man and three passengers were killed in a high-speed crash of a Lexus ES sedan. Before the crash, the driver called 911 to report that the gas pedal was stuck and that the car was going 120 mph.
Toyota has received complaints from consumers about floor mat entrapment since 2004.
The safety administration said it approached Toyota regarding the issue in the RX models last month after the agency observed an increase in consumer complaints and other reports regarding pedal entrapment in the vehicles.
"When Toyota confirmed last week that it had received a significant volume of complaints on the same issue, NHTSA asked the manufacturer to conduct a recall," the safety agency said.
It is also asking for more information from the automaker.
"NHTSA urges consumers impacted by the recall to immediately remove the floor mat and have their vehicles serviced promptly," the agency said. "While NHTSA anticipates the remedy proposed by Toyota will address the problem, the agency will continue to monitor the issue and will take appropriate action as warranted."
The latest recall comes as Toyota is on an upswing, having rebounded from last year's earthquake and tsunami in Japan and flooding in Thailand. Inventory levels are back up and sales have surged.
Through the first five months of this year, Toyota has sold more than 868,000 vehicles, a 24% gain from the same period a year earlier. Its share of the U.S. auto market has grown to 14.5% from 13.3%, according to Autodata Corp.
Auto analysts said they didn't expect the latest round of recalls to negatively affect Toyota's sales or brand perception.
"The recalls really didn't seem to do much damage to Toyota in terms of lasting impact," said Aaron D. Bragman, a senior analyst at IHS Automotive. "People who were loyal to Toyota continued to be loyal to Toyota."