The Obama administration has quietly dropped from its lexicon the phrase 'war on terror,' coined by former President George W Bush to defend many of his controversial actions.

"I haven't gotten any directive about using it or not using it. It's just not being used," Secretary of State Hillary Clinton told reporters aboard her aircraft on way to The Hague to attend an international conference on Afghanistan.

"The administration has stopped using the phrase and I think that speaks for itself," she said at a different point during her trip, ABC News reported.

The discontinuation of the term 'war on terror' marks a departure from the practice of the Bush administration which began using the phrase in the wake of the September 11, 2001 attacks on the World Trade Centre and Pentagon.

Many in the international community, including human rights groups, had objected to the term, finding it overly broad, including to justify actions like the opening of the Guantanamo Bay prison for detainees held without trial at the US naval base in Cuba.

Since taking office on January 20, US President Barack Obama has reversed some of Bush's decisions, ordering the closure of Guantanamo within a year and an end to harsh interrogation of terrorism suspects.