Mexico City  - US President Barack Obama arrived in Mexico Thursday for an overnight visit to meet with Mexican President Felipe Calderon.

"Geography has made us neighbours. History has made us friends. Economics has made us partners and necessity has made us allies," Calderon said as he welcomed Obama, quoting the late US president John F Kennedy.

Discussions are set to focus on drug trafficking and crime, as the death toll in Mexico's drug wars has soared to more than 7,000 since January 2008.

Obama praised Mexico for having "so courageously taken on the drug cartels," and stressed his government's commitment to stopping the flow of guns and cash that come into Mexico from the United States.

The US government has conceded in recent weeks that the two countries share responsibility on this issue, as drugs flow north and weapons flow south.

While Calderon hailed "the opportunity of a new era of trust," Obama said that "Mexico is not just a regional leader but also a global leader."

"It's critical that we join together around issues that cannot be solved by any one nation," Obama said.

He recalled that about 33 per cent of people in Chicago, his home city, are of Mexican heritage.

The delegations from the two countries were set to meet later, prior to a private meeting between their two leaders.

This is the first visit to Mexico City by a US president since then-president Bill Clinton in 1997.

From Mexico, Obama is to fly Friday to Trinidad and Tobago for the Summit of the Americas. (dpa)