Washington, Aug 14 - Concerned over a new public opinion poll in Pakistan showing that 64 percent Pakistanis see America as the enemy, Defence Secretary Robert Gates says the US must maintain relationships with Pakistan for the long term to build trust.

The poll saying only 9 percent of Pakistanis see the US as a partner is disturbing to defence leaders, but not surprising, he said during a Pentagon news conference Thursday.

'First of all, one of the reasons that the Pakistanis have concerns about us is that we walked away from them twice,' he said.

The United States left Pakistan after the Soviets left Afghanistan, and later in the 1990s cut off military contacts with Pakistan in response to Pakistan's pursuit of nuclear weapons.

'So, our military-to-military relations were significantly interrupted,' Gates said. 'I think that the Pakistanis, with some legitimacy, question how long are we prepared to stay there?'

The Pakistani people wonder if the only reason the United States is working with the government is 'because of the war in Afghanistan, or do we value Pakistan as a partner and an ally independent of the war in Afghanistan?' he said.