WASHINGTON, April 30: White House counter-terrorism adviser John Brennan offered a rare public defence of drone strikes on Monday and said the attacks were legal and ethical and were directed only at “legitimate military targets”.

In an indirect reference to Pakistan, Mr Brennan said the country’s reluctance to act against certain terrorists also justified the US decision to use unmanned aircraft for targeting militant hideouts in Fata.

“There’s nothing in international law that bans the use of remotely piloted aircraft … or that prohibits us from using lethal force against our enemies outside of an active battlefield, at least when the country involved consents or is unable or unwilling to take action against the threat,” he said.

At a two-day seminar in Washington this weekend, peace activists urged the US government to immediately halt the strikes because they were “illegal and unethical” and were also killing innocent civilians.

In the first ever detailed US policy statement on drones, Mr Brennan rejected both arguments and indicated that drone attacks on terrorist targets would continue.

In a speech marking the anniversary of Al Qaeda leader Osama bin Laden’s elimination, Mr Brennan said the strikes were used only in cases of a “significant threat”.

He said the US Constitution empowered the president to protect his nation from any imminent threat of attack.