Efforts to stop immigration and the mix of cultures are bound to fail, Mexico¡¯s President Enrique Pena Nieto told a United Nations summit on migrants and refugees on Monday, as his country¡¯s northern border has become an issue in the U.S. presidential election campaign.

Pena Nieto took a public opinion shellacking for hosting Republican Party candidate Donald Trump on Aug. 31 because Trump has repeatedly vowed to build a border wall to keep out illegal immigrants and said Mexico would pay for it.

¡°History shows that there are no barriers that can stop either the movement of people or the fusion of cultures,¡± Pena Nieto said in his address to the summit ahead of the U.N. General Assembly.

¡°Neither natural nor artificial barriers hold sway. For every river there has always been a bridge. For every obstacle there has always been a way forward. Movement is an essential part of human existence,¡± he said.

Trump has infuriated Mexicans with a series of broadsides against the southern neighbor.

¡°We are a proudly mestizo, multicultural and diverse nation,¡± Pena Nieto said, referring to Mexican of mixed descent.

¡°We Mexicans firmly believe that this mestizo fusion is the future and destiny of human kind.¡±

Hillary Clinton, the Democratic Party candidate in the Nov. 8 election, has accused Trump of embracing a brand of U.S. political conservatism associated with white nationalism and nativism.

She has linked Trump¡¯s statements about immigration and religion to the rise of a political fringe movement in the U.S. known as the ¡°alternative right,¡± which opposes multiculturalism and immigration.