A powerful Republican senator on Friday scolded Donald Rumsfeld, complaining that the US defence secretary's comments about Hugo Chávez, the Venezuelan president, could hurt anti-drug efforts in the region.

The rebuke by Arlen Specter, chairman of the judiciary committee, comes at a crucial moment for both men. Mr Rumsfeld faces scrutiny for his conduct of the war in Iraq, while Mr Specter, a moderate sometimes distrusted by conservatives within his own party, is to lead next month's confirmation hearings of John Roberts, President George W. Bush's Supreme Court choice.