Mexican President Felipe Calderon said on Tuesday he was willing to look at US concerns over trade but denied he had discussed renegotiating the North American Free Trade Agreement with US President-elect Barack Obama.
The Mexican government has been worried about Obama's campaign promise to renegotiate Nafta with the United States' two partners, Mexico and Canada.
After his final White House meeting with President George W Bush a week before he hands over to Obama, Calderon joined his host in hailing the benefits of Nafta, saying it had created jobs on both sides of the US-Mexican border.
"As I indicated to President-elect Obama yesterday, we are willing to build on the foundation of what the free trade agreement has gained in order to focus on improving the benefits," Calderon said with Bush at his side in the Oval Office.
Nafta has greatly expanded Mexican trade with its powerful neighbour since it went into effect in 1994, but US labour unions see it as a cause of job losses in big industrial states.
Calderon said Mexico was also prepared to "look into, as we have always been willing to do, any issues of concern not only to Americans but also to Mexicans", and he cited labour as one of those issues.
But he denied he had discussed renegotiating the treaty with Obama, who takes office on January 20.
"We did not speak about the issue of reopening or renegotiating" Nafta, Calderon told reporters on the plane taking him back to Mexico. "What he emphasised was his concern about environmental and labour issues," said Calderon, a conservative.
Calderon told international business leaders in November, following Obama's election victory, that restricting trade would only drive more Mexicans to cross the border illegally into the United States.
"Renegotiating Nafta is a very bad idea," Calderon said at a meeting of Asian and Pacific leaders in Peru.
In Washington on Monday, Obama told Calderon he would work to strengthen US ties with Mexico but did not mention Nafta in his remarks to reporters after their meeting.