Relations between Mexico and the US are at a critical stage, said Geronimo Gutierrez, nominee for Mexican ambassador to the US.

Gutierrez, former deputy minister of foreign affairs for North America and a prominent defender of NAFTA, said that any deepening of the current crisis could lean to a "major derailment."

Speaking to lawmakers of the Democratic Revolution Party (PRD), Gutierrez said that dialogue had to be maintained as there is "the possibility of building a far better relationship', Xinhua news agency reported on Friday.

On Thursday, Mexico's President Enrique Peña Nieto submitted the candidacy of Gutierrez as Mexican ambassador to the US to the Senate, adding that he had the approval of the US government.

Speaking to the senators, Gutierrez admitted that he would not accept the responsibility of representing Mexico without believing he could seek a closer relationship with the US

"I am fully aware that there may be no changes… that go against the national interest," he added.

However, while Gutierrez said the relationship was currently "atypical," he said that "the level of evolution seen in bilateral ties in recent years cannot be understated." 

Gutierrez has been a public official in the last four Mexican governments, holding positions in the ministries of commerce, finance, foreign affairs, and national security.

His last role was as managing director of the North American Development Bank in San Antonio, Texas, which was created within the NAFTA deal.