It's all about relationships in Mexico, says Mr Alfred Chan, 62, Mexico's oldest Singaporean resident, who arrived to live there in 1999.

Mr Chan is married to a Mexican, Diana, 49, and the two have a 14-year-old daughter. Originally relocated to manage a factory for a Singapore-based company, he stayed on after the plant was shut down and moved to China in 2003. Now, he deals in industrial LED lighting.

They live in a quiet town, Hermosillo, the capital city of Sonora state. It is far from the humming cosmopolitanism of Mexico City, but just a four-hour drive to Tucson, Arizona in the United States.

"If Singaporeans want to come here there are a lot of opportunities," Mr Chan told The Straits Times. "Mexico has everything - oil and gas, copper and gold, vegetables and seafood. The Chinese have lately been flooding in, especially in the seafood sector, they ship seafood back to China.

"But Singaporeans have to change their mindset. They must be careful in their dealings, and work with a local. Over here, they would rather do business with relatives or friends, not outsiders," he said. "It took me around five years to build up that trust."

The message is echoed by Mr Tan Zheng Yu, a 35-year-old Singaporean shipping executive who has lived in Mexico City for two years, with his wife and a young daughter. "Mexico is similar to doing business in China," Mr Tan said. "Asians have so much more similarities to Latin Americans than one can imagine. Culturally... if a Singaporean company has experience doing business in China, you can do business in Mexico."

But in Mexico it is about trust, not contracts, he said. "Rather than hanging everything on a contract like in the US, here it is about relationships, it's about whether you are comfortable with a person."

While most Mexicans he meets do not know where Singapore is, those who do have great admiration, he has found. "Even in a remote part of Mexico a taxi driver may ask me where I am from and when I say Singapore, they say 'a rich country, with no corruption'.

"People trust Singapore companies, trust our expertise and professionalism. I would still say probably 90 per cent of the population doesn't know what Singapore is, but for people who know Singapore, it's always in a very positive light."

The value of bilateral trade between Mexico and Singapore in 2017 was $4.5 billion. Over 40 Singapore firms currently operate in Mexico in sectors like oil and gas, manufacturing, infrastructure, engineering and consumer products, Enterprise Singapore says. These include Banyan Tree, Fagerdala, Hyflux, Kaybee Group, Olam, Temasek, Surbana Jurong, ST Electronics and Sunningdale. Singapore's direct investments in Mexico hit $1.08 billion at end-2016.

Most of the firms employ locals, said Enterprise Singapore regional director for Mexico Francisco Rios, who is an example himself - a half Italian from Venezuela. Singapore's Honorary Consul General in Mexico, Mr Eduardo Henkel, is a Mexican businessman who controls most of the BMW market in Mexico - including a line of bullet-proof BMWs.

Mr Chan manages to go back to Singapore once every year or two, he said. And what does he enjoy the most when he is back? Of course, one of Singapore's signatures - hawker food, he said with a laugh.

Correction note: An earlier version of the story wrongly stated that Mr Francisco Rios was the centre director for Mexico, emerging Europe, Latin America and the Caribbean of International Enterprise (IE) Singapore. We are sorry for the error.