Mexican President Felipe Calderon has signed into law a constitutional change eliminating the "pocket veto," a measure that formerly allowed presidents to kill legislation by refusing to sign it.
The old system let a Mexican president kill a bill by simply ignoring it.
Now the president will have 30 days to either approve a bill or return it to Congress for reconsideration, which is Mexico's equivalent of a veto. Legislation will automatically be considered to be enacted as law if the president fails to act within 30 days.
A Tuesday statement from Calderon's office says the change will strengthen democracy and cooperation between the branches of government.