The United States Attorney General has defended the Bush Administration's domestic surveillance programme.
Alberto Gonzales told the Senate Judiciary Committee that US President George W Bush was fully empowered to authorise the phone-tapping of American citizens as part of the war on terror.
Opposition Democrats and some Republicans had suggested that some of the measures had gone too far.
The committee began a series of hearings this week on President Bush's controversial domestic surveillance programme.
The Bush Administration says it is necessary to monitor any phone contact between people in the US and suspected al-Qaeda members abroad.
Critics say it is against the law.
Mr Gonzales faced tough questioning from both Democratic and Republican senators who wanted to know why the administration did not inform Congress of the programme.
Senators also wanted to know why it ignored an existing law that requires court warrants to place wire taps on phones.
Democratic Senator Pat Leahy accused the administration of acting illegally without safeguards.
Mr Gonzales said Mr Bush had the right to order the programme because the Constitution gives him ‘extraordinary’ powers during wartime.
