Assistant Secretary of State Richard Boucher praised Islamabad for arresting key leaders of Lashkar-e-Taiba (LeT) and closing the offices of the charity Jamat-ud-Dawa, which is widely believed to be a front for the banned group.

But he told a news conference in Mumbai: 'It's a promising start and there's a lot more to do.'

Ten attackers allegedly trained, equipped and financed by LeT hit Mumbai on Nov 26-29 last year, leaving 165 civilians and security personnel dead and more than 300 others injured.

The strikes raised tensions between India and Pakistan, with New Delhi accusing Islamabad of not doing enough to tackle Islamist extremists based there and of state agencies giving tacit support to the groups.

Boucher, who has responsibility for south and central in the State Department, arrived in Mumbai from New Delhi after visits to Islamabad and Kabul.

He told reporters here that tackling extremism was a 'big task' and required co-operation on all sides, pledging Washington's continued support to help achieve it.

Civilian and military leaders in Pakistan were 'determined to rid their country of terrorism", he added, but cautioned that no extremist groups could be allowed to remain there for the safety and security of its neighbours.

'Pakistan increasingly understands that,' he added. -- AFP