Oklahoma and Nebraska filed a lawsuit against neighboring Colorado in December for legalizing recreational marijuana and making it more difficult to enforce their state laws, but other nearby states aren’t jumping in to join the suit.

Kansas Attorney General Derek Schmidt (R) said his state isn’t part of the lawsuit “at this time.” “Colorado’s decision to legalize marijuana and the federal government’s subsequent decision to limit enforcement of federal law in Colorado have combined to cause harm in Kansas, and we are assessing our options,” he said in a statement.

Utah Gov. Gary Herbert (R) told reporters Tuesday at the National Governors Association State of the States address in Washington that Utah had “no plans to sue Colorado.”

The Washington Post did not receive responses from Wyoming Attorney General Peter Michael (R) or the office of New Mexico Attorney General Hector Balderas (D) about whether they would sue Colorado.

Oklahoma and Nebraska argue in their suit that Colorado’s marijuana policy violates the U.S. Constitution and is a burden on neighboring states’ law enforcement.

“The Constitution and the federal anti-drug laws do not permit the development of a patchwork of state and local pro-drug policies and licensed-distribution schemes throughout the country which conflict with federal laws,” the complaint reads.

Seven Oklahoma Republicans have come out against the lawsuit, saying it endangers states’ 10th Amendment rights and are asking Attorney General Scott Pruitt (R) to “quietly drop” the suit.