President Donald Trump's plan to blacklist the Muslim Brotherhood as a terrorist group will deal a major blow to democratization efforts in the Middle East, the ruling Justice and Development Party (AK Party)'s spokesman said Tuesday.

Speaking after the party's Central Executive Board (MYK) meeting, Ömer Çelik said Trump's potential move would increase Islamophobia in Europe and the U.S., and strengthen extreme rightists.

Such a decision by the United States would "undoubtedly yield extremely wrong results regarding stability, human rights, basic rights and freedoms in countries of the Islamic world", he said, adding "At the same time, (Trump's move) is the biggest support that can be given to the propaganda of Daesh."

The designation would pave the way for American sanctions on the transnational movement, which has supporters throughout the Arab and wider Muslim world.

The White House earlier signaled such a move could be imminent, saying after Trump met with Egyptian President Abdel Fattah al-Sissi April 9 that the leaders discussed "the threat posed by the Muslim Brotherhood."

It is unclear if the administration is seeking to designate Egypt's Muslim Brotherhood, its worldwide offshoots or a combination thereof.

Ousted Egyptian President Mohamed Morsi, who had the brotherhood's backing, won Egypt's first democratic elections in 2012, but was removed from power by the Egyptian military following mass demonstrations roughly a year later.

Sissi helped lead the coup that removed Morsi from power.

In addition to the Egyptian leader, the designation would squarely place the U.S. alongside Saudi Arabia, the United Arab Emirates and Bahrain who all oppose the Muslim Brotherhood.

'EU becoming bastion of far-right, racists'

On a separate note, Çelik slammed Manfred Weber, Germany's center-right European People's Party candidate and front-runner to replace Jean-Claude Juncker as president of the European Commission, who openly called on the bloc to end its accession negotiations with Turkey as it did not fit in with its "Christian values".

"The European Parliament used to be called a cradle of democracy. Nowadays, it is turning into a bastion of far-right, racist politics," Çelik said.

Turkey applied for EU membership in 1987 and accession talks began in 2005.

But negotiations stalled in 2007 due to the objections of the Greek Cypriot administration on the divided island of Cyprus as well as opposition from Germany and France.