Former President Donald Trump continued challenging Republican incumbents by endorsing Kelly Tshibaka in her battle to unseat Alaska Sen. Lisa Murkowski, one of the GOP senators who voted to convict him in his impeachment trial.

Trump called Murkowski “bad for Alaska” in a statement Friday endorsing Tshibaka, a former Alaska Department of Administration commissioner. He cited Murkowski’s vote to confirm Deb Haaland, President Joe Biden’s nominee for Interior secretary, which the former president said was “a vote to kill” drilling in the Arctic National Wildlife Refuge and jobs.

Earlier this month, the Biden administration suspended Arctic refuge drilling rights that were sold in the final days of Trump’s presidency, dealing a victory to environmentalists who have argued for decades against oil development in the remote, wild region of Alaska.

“Murkowski has got to go!” Trump said in the statement. “Tshibaka is the candidate who can beat Murkowski — and she will.”

Murkowski was one of seven GOP senators who voted to convict Trump in his impeachment trial following the deadly Jan. 6 riot at the U.S. Capitol to stop the counting of Electoral College votes for Biden. Trump has vowed to defeat Murkowski and Republican House members who voted to impeach him.

Trump also said he would campaign for Tshibaka. Trump is holding his first campaign-style rally since leaving office in Ohio on June 26 to support Max Miller, the Republican challenger to Rep. Anthony Gonzalez, one of the 10 House Republicans who impeached the former president.