US: The White House has sought to play down a dispute with Mexico over Washington's decision to build a 700-mile fence along the border in an attempt to keep illegal immigrants out. President George Bush signed the border fence Bill on Thursday but Mexico's president-elect, Felipe Calderon, described the fence as a grave error and compared it to the Berlin Wall.
"The president understands the sensitivities, but on the other hand, he also understands the importance of securing the border.
"And as we have pointed out on a number of occasions, you have fences in some places - you really have a mix of fences, border patrol agents, technical means, surveillance and that kind of thing, so it's not strictly fences," White House spokesman Tony Snow said.
Signing the Bill, Mr Bush said he remained committed to comprehensive immigration reform, including a mechanism to allow illegal immigrants to remain in the US and eventually apply for citizenship.
"We must face the reality that millions of illegal immigrants are already here. They should not be given an automatic path to citizenship; that is amnesty. I oppose amnesty.
"There is a rational middle ground between granting an automatic pass to citizenship for every illegal immigrant and a programme of mass deportation.
"And I look forward to working with Congress to find that middle ground," Mr Bush said.
Immigration rights activists are hoping that a Democratic victory in next month's congressional elections could produce an agreement on immigration reform between the Senate and the House of Representatives.