Image taken on Feb 3, 2016 shows a red-eyed frog resting on a leave vine in the tropical rainforest in the Guayabo National Monument, 70km from San Jose, Costa Rica. In a small territory of 51,100 square kilometers, Costa Rica is home to approximately 3.6 percent of the expected biodiversity on the planet (estimated between 13 and 14 million species, 5 percent of known registered biodiversity science. (Xinhua/Kent Gilbert)

CANCUN, Mexico, Dec. 2 (Xinhua) -- Countries must unite to defend biodiversity instead of building border walls, Erik Solheim, executive director of the United Nations Environment Programme (UNEP) said Friday.

"The United States, Mexico, Europe and China, if they work together toward common solutions, they can achieve miracles, such as the Paris Agreement and the Sustainable Development Goals," said Solheim, ahead of the 13th Conference of the Parties to the Convention on Biological Diversity (COP13) to be held from Dec. 4-17 in Cancun, Mexico.

"It is crucial for all countries and sectors to work together to attack the problems afflict the plant, such as the lack of biodiversity," the official added.

Solheim also took shots at U.S. President-elect Donald Trump's plan to build a border wall along the Mexican border to keep immigrants out.

Pointing out that global efforts have achieved landmark results, such as reducing hunger in Africa by 70 percent, Solheim stated political forces should stand together.

According to Solheim, if political forces are allowed to divide humanity, lofty goals will fail and tourism, environment, and biodiversity will all suffer.

Mexico's Environment Minister Rafael Pacchiano also said he would seek to build links with the incoming Trump administration to protect the environment.

The COP13 will be officially held on Sunday, and around 200 ministers and envoys from around the world have begun discussing actions needed to protect biodiversity since Friday.