Mexico's newly-elected President Andres Manuel Lopez Obrador has vowed to “seek friendship” with Donald Trump.
During a half-hour telephone conversation, Mr Trump said the two leaders discussed topics including border security, trade and the North American Free Trade Agreement.
Mr Trump said: "I think the relationship will be a very good one."
In an interview with the Televisa news network, Mr Lopez Obrador did not provide specifics on what an "understanding" with the Trump administration might look like.
"We are conscious of the need to maintain good relations with the United States. We have a border of more than 3,000 kilometres, more than 12 million Mexicans live in the United States. It is our main economic-commercial partner," he said.
"We are not going to fight. We are always going to seek for there to be an agreement... We are going to extend our frank hand to seek a relation of friendship, I repeat, of co-operation with the United States."
Meanwhile, members of the business and political elite who fiercely opposed Mr Lopez Obrador's populist candidacy pledged to support his presidency in a loyal opposition.
With nearly three-quarters of the ballots counted, Mr Lopez Obrador had about 53 per cent of the vote - the most for any presidential candidate since 1982, a time when the Institutional Revolutionary Party was in its 71-year domination of Mexican politics and ruling party victories were a given.
Rivals Ricardo Anaya and Jose Antonio Meade acknowledged Lopez Obrador's win even before official results were announced, in a break from
past elections.
Mr Lopez Obrador himself refused to accept his two previous presidential losses, and in 2006 his supporters set up a protest camp that caused months of chaos in Mexico City.
He announced a team of advisers that includes prominent businessman Alfonso Romo - a friend of telecom magnate Carlos Slim, one of the world's wealthiest people - and widely respected politician Tatiana Clouthier, formerly a member of Mr Anaya's conservative party, apparently seeking to signal that nobody should fear his promise of "profound change".
