Pic: AP.

Pic: AP.

WELLINGTON, New Zealand (AP) — Environmentalists say that Russia and China have blocked a plan to create the world’s largest marine reserve in a vast swath of ocean off the coast of Antarctica.

The countries that make decisions about Antarctic fishing finished a 10-day meeting late Friday in Hobart, Australia, without reaching the required consensus to move ahead with the plan. It’s the fourth time the plan has failed.

Most of the 24 nations and the European Union favored the U.S.-New Zealand proposal to ban most fishing in a sanctuary sprawling across 1.3 million square kilometers (517,000 square miles), or twice the size of Texas, in the Ross Sea.

The Antarctic Ocean Alliance says Russia and China blocked the plan. The outcome raises questions about the ability of the nations to deliver on conservation commitments.