Despite mounting US pressure, Pakistan President Asif Ali Zardari has reportedly decided to travel to Tehran this week to finalise a multibillion dollar gas pipeline deal. 
Under the agreement, Iran would offer a loan of 500 million dollars to Pakistan for the construction of a gas pipeline on its side of the border. However, the project has run into trouble due to an absence of investors fearing economic sanctions by the US, reports The Express Tribune.
A foreign ministry official confirmed that Zardari will begin a two-day visit to Iran on Tuesday to finalise the much-anticipated deal.
The official disclosed that Washington was pushing hard to convince Islamabad to abandon the project.
Meanwhile, at his weekly briefing on Thursday, foreign ministry spokesperson Moazzam Ali Khan rejected reports of US pressure insisting that the Iran-Pakistan (I-P) gas pipeline project was "enormously important" for an energy deficient country like Pakistan.
Iran  will also set up an oil refinery in Gwadar, Balochistan, it was revealed.
And both the formal agreements would be inked between leaders of the two countries during the president's upcoming visit to Tehran.
The 4 billion dollar refinery is slated to be constructed in the port city of Gwadar with an estimated capacity of about 400,000 barrels per day.
The proposed cooperation between Islamabad and Tehran  is likely to invite more pressure from Washington, sources say.
The US State Department said on Saturday that there were better options available for Pakistan than the I-P project to meet the country's growing energy demands.
But, Pakistan so far resisted the pressure and has decided to go ahead with the project.
Last week, the Iranian oil minister visited Islamabad and said Tehran would start supplying natural gas to Pakistan by December 2014.