Islamabad:  Pakistan's president vowed to continue with a proposed pipeline project with Iran despite American warnings of sanctions, saying Islamabad's relations with Tehran would not "be undermined by international pressure of any kind."

Asif Ali Zardari made the comments alongside Iranian President Mahmoud Ahmadinejad, who is facing fresh Western pressure over his country's nuclear programme.

Pakistan faces chronic energy shortages that feed anti-government anger, hobble industry and trigger unrest in an already poor country. The proposed pipeline would deliver natural gas from Iran to Pakistan, and go some ways to improving the situation.

But the US wants Pakistan to halt the project because it would undercut international pressure to isolate Iran over its nuclear programme. The issue is an irritant, though by no means the largest, in already badly strained relationship between Islamabad and Washington.

Iran maintains its nuclear programme is entirely peaceful, but the US and its allies worry the programme is designed to ultimately deliver a nuclear weapon.

President Asif Ali Zardari was asked about the opposition to the project.

"Pakistan is lobbying the world, and our point of view is being accepted," he said. "Our bilateral relationships cannot be underminded by any international pressure of any kind."

The project was first proposed in the 1990s, but has been plagued by delays. The deal was finalised last year. Under the contract, Iran will export 21.5 million cubic metres of gas per day to Pakistan through a new $7 billion (Dh25.7 billion) pipeline beginning in 2014.