Republican Sen. Dean Heller of Nevada says Cliven Bundy should pay the Bureau of Land management more than $1 million in grazing fees the agency says he owes.
Heller made no additional comment on the subject at a news conference in Washington.
A Nevada rancher, Bundy says he doesn't recognize federal authority over lands around his property where his cattle have long grazed.
The BLM claims the cattle are trespassing on fragile Gold Butte habitat set aside for the endangered desert tortoise, and that Bundy owes $1.1 million in fees and penalties since 1993.
A recent armed standoff during a BLM roundup of the family's cattle earlier this month became so tense that the agency stopped its efforts, released about 350 animals back to Bundy and left the area.