United Nations Secretary-General Ban ki Moon [Images] on Tuesday said he had impressed upon top Pakistani leadership, including President Asif Ali Zardari [Images] and Prime Minister Yousuf Raza Gilani [Images] that they should fully cooperate with India and thoroughly investigate the Mumbai [Images] terrorist attacks.

Addressing a press conference on returning from his visit to India and Pakistan, he said the Pakistani leaders had 'committed to me that they will fully cooperate' with India in the investigation.

"During my visit to India and Pakistan, I was reasonably relived and also gratified that leaders of both countries are committed to cooperating" to resolve the issue, he added.

Pakistan Prime Minister Gilani, he said, had told him that Islamabad [Images] was in the process of enacting a legislation by which they can punish those who commit crimes outside their territory. "That is very commendable," he added.

Asked about the Kashmir issue, Ban said the relationship between the two countries is so important for the subcontinent and the region that all the pending issues should be resolved through composite dialogue they had initiated.

The world leaders, including Ban, had urged leaders of both countries to calm down when their relations were 'very tense' after the Mumbai attacks. They had appealed to India and pakistan to resolve the issue through bilateral talks.