Mexico City - The Mexican president has nominated a new ambassador to the United States, one who has experience "defending the interests of Mexico abroad."

Tuesday's announcement appears to be the latest move in a growing effort by Mexico to stand up for itself in the U.S. and on the global scene in the face of persistent attacks by the Republican presidential front-runner.

Trump has promised to build a giant wall to keep out undocumented immigrants from Mexico, a group he's described as drug dealers and "rapists." He also insists he'll force Mexico to pay for the wall, even threatening to ban Mexicans in the U.S. from sending money back home unless the Mexican government coughs up billions for the structure.

Mexican leaders have balked at the notion that they'll pay for any wall, while also quietly reaching out for months to allies in the U.S. to shore up their image in the face of Trump's attacks. The diplomatic changes suggest that Mexican President Enrique Peña Nieto wants his country's diplomats to take a more active, public approach.

The newly nominated ambassador is Carlos Manuel Sada Solana, a man with an extensive diplomatic resume, especially in the United States, who currently serves as consul general of Mexico in Los Angeles. Sada "has broad experience with consular work and protecting the rights of Mexicans in North America, as well as defending the interests of Mexico abroad," Mexico's Foreign Ministry said in its announcement.

In particular, the ministry noted that Sada had previously worked as minister for congressional affairs in Mexico's embassy in Washington, "something which allowed him to develop close relations with, and gain an understanding of, the legislative bodies of the United States."

Sada replaces Miguel Basañez Ebergeny, who took the helm as ambassador around seven months ago. Basañez, who has an academic background, comes across as a genial man who has tried to downplay the Trump effect, at least in public, while stressing the longstanding ties between the U.S. and its third-largest trading partner. Several months ago, the outgoing ambassador said that Trump would have to apologize for his comments about Mexico, something the real estate mogul appears unlikely to do anytime soon.

The Foreign Ministry also announced that José Paulo Carreño King has been nominated as Mexico's undersecretary for North America. Paulo Carreño has an extensive public relations background, not just in the government sector but also in the financial world, where his employers have included Citigroup among others, according to the announcement.

"The designations of Paulo Carreño King and Carlos Sada Solana are part of an integral strategy that the Government of Mexico will employ to strengthen relations, the promotion of Mexican interests, and the image of our country in Canada and the U.S.," the Foreign Ministry said.