WASHINGTON • President Joe Biden, whose elder son Beau died of cancer years after deploying to Iraq, signed legislation Wednesday expanding federal health care services for millions of veterans who served at military bases where toxic smoke billowed from huge “burn pits.”

“We owe you,” Biden said. “You’re the backbone. You’re the steel. You’re the sinew. You’re the very fiber that makes this country what it is.”

The law, which Biden described as long overdue, caps a years-long battle to ensure treatment for chronic illnesses that veterans have blamed on burn pits, which were used to dispose of chemicals, tires, plastics, medical equipment and human waste on military bases. Estimates of affected troops run to 3.5 million.

“So many of you here today remind us that we have fought for this for so many years,” he said during a White House ceremony .

Biden was introduced by Danielle Robinson, the widow of Sgt. 1st Class Heath Robinson, who died of cancer two years ago. The legislation is named for him. She described her late husband as “a soldier as strong as an ox” but also “the ultimate cuddler” for his daughter Brielle, who stood to her mother’s side clutching a stuffed figurine wearing military camouflage.

President Joe Biden gives the pen he used to sign the “PACT Act of 2022” to Brielle Robinson, daughter of Sgt. 1st Class Heath Robinson, who died of cancer two years ago, during a ceremony in the East Room of the White House, Wednesday, Aug. 10, 2022, in Washington. (AP Photo/Evan Vucci)

Evan Vucci