Brussels  - NATO could curtail or scrap a planned goodwill visit of a flotilla of warships to Pakistan, Singapore and Australia in a bid to fight pirate attacks in the waters off Somalia, the alliance's spokesman said Wednesday.

NATO currently has four frigates in the Gulf of Aden fighting piracy. They are set to leave the region on Thursday and visit Karachi, Singapore and Perth in a show of diplomatic goodwill, before returning to anti-piracy tasks in late June.

But NATO ambassadors are now debating whether that schedule can go ahead as planned, or whether the Asia-Pacific tour should be cut to keep the ships in Somali waters longer or bring them back sooner, James Appathurai told journalists in Brussels.

A steep rise in pirate attacks in the waters off Somalia in recent months has put increasing pressure on the international community to commit more forces to the region.

But NATO is keen to strengthen its ties with Pakistan, Singapore and Australia, all of whom are seen as important supporters of the alliance's ongoing mission in Afghanistan.

The ambassadors are also deliberating whether NATO should set up a longer-term anti-piracy mission to complement a task force sent by the European Union to the Gulf of Aden, Appathurai said.

And they are debating whether there is some way to change their ships' rules of engagement so that they can arrest pirates caught in the act of attacking passing ships.

Currently, each ship operates under its national laws, and some NATO members have no laws on piracy on the high seas. That led to a case at the weekend in which NATO ships detained seven armed pirates but were forced to release them immediately.

NATO Secretary General Jaap de Hoop Scheffer is "not happy with the mission they have, nor happy with the authorities they have been given," Appathurai said. (dpa)