CANBERRA, Australia — Two anti-nuclear weapons campaigners scaled the entrance awning of Australia’s foreign ministry and unfurled a banner on Wednesday to protest the government’s failure to endorse a U.N. nuclear disarmament treaty.

Gem Romuld and Papatya Danis spent three hours on the Department of Foreign Affairs and Trade building near Parliament House in the national capital Canberra holding the banner: “Sign nuclear weapons ban treaty.”

Scores of police were soon on the scene and the two climbed down and were released without charge.

“I think we’ve made our statement and hopefully brought some attention to Julie Bishop’s failure to sign Australia on to the treaty,” Romuld said.

Australia has joined nuclear-armed countries including the Unites States, a staunch ally, in boycotting the first treaty to ban nuclear weapons.

The Treaty on the Prohibition of Nuclear Weapons opens for signatures Wednesday at the U.N. General Assembly’s annual ministerial meeting attended by Foreign Minister Julie Bishop in New York.

Sue Wareham, board member of the International Campaign to Abolish Nuclear Weapons, told reporters outside the Canberra building that her lobby group had done all it could through “legitimate channels” to get the government to change its stance.

“We need to get the message out to the Australian people that we expect better from our government, we want them to engage in this nuclear disarmament initiative,” Wareham said. “Our government is not representing us on this issue.”

Australia argues that it is protected by an umbrella of deterrence created by U.S. nuclear weapons.

Australian diplomats are also skeptical about the treaty’s ability to reduce the number of nuclear weapons.

Bishop said in a statement that she would “continue Australia’s tireless efforts to achieve a world free of nuclear weapons.”

She said she would promote the Comprehensive Nuclear-Test-Ban Treaty in New York and would work with ministerial counterparts from the 12-member Non-Proliferation and Disarmament Initiative on practical initiatives to strengthen the Nuclear Non-Proliferation Treaty.

“My focus will be on the practical and effective steps required for real progress on nuclear disarmament,” Bishop said.