President Donald Trump says he's still "thinking about" whether or not the federal gas tax should be suspended, he told Townhall on the White House South Lawn on Tuesday afternoon.

A federal gas tax suspension would require the approval of Congress, which is out until the midterms. Regardless of timing, a suspension signed by the president would shave off 18.4 cents per gallon, and 24.4 cents off diesel. States have their own separate gas tax, including California’s nearly 63-cent tax.

The average price of gas is $4.36 per gallon, and it’s become a hot topic on the campaign trail amid the conflict between the U.S. and the Islamic Republic of Iran. 

Trump was also supportive of the proposal in May, telling CBS News at the time that "we’re going to take off the gas tax for a period of time, and when gas goes down, we’ll let it phase back in," calling it a "great idea."

Republicans and Democrats have proposed bills for a suspension, including Sen. Josh Hawley (R-MO) and Sen. Mark Kelly (D-AZ). 

“Arizonans are getting squeezed by high costs. Fuel prices are skyrocketing because of Trump’s war in Iran,” Kelly said in a late September statement. “Suspending federal fuel taxes will put money back in people’s pockets. Families need help, and I’m focused on lowering their costs.” 

In May, Hawley said "President Trump has proposed to suspend the federal gas tax and he’s exactly right."

Trump’s comments come in the backdrop of an Executive Order signed by the president this week allowing American diesel drivers to buy red dye diesel on a “deferred” tax basis.

“Farmers and truckers are essential to the American way of life.  Restricted global diesel supply has led to rising prices, and these key industries have been particularly hard hit,” the executive order stated. “While my Administration has already undertaken historic efforts to ensure fuel affordability for our citizens, it is clear that further temporary relief is necessary.”

In September, Gov. Brian Kemp (R-GA) suspended his state's 33-cent gas tax through the end of October.

“Over the past several years, with the help of our partners in the General Assembly, we've been able to give billions of dollars in relief to hardworking Georgians,” Kemp stated at the time. “We've remained committed to helping them and our small businesses fight through the tough times, and that's why I'm taking this action today to give further relief.”