Construction of BP’s controversial $3bn (£1.6bn) oil pipeline from the Caspian Sea to Turkey resumed only after the intervention of Donald Rumsfeld, the US Secretary of Defense, and other senior members of the Bush administration, it has emerged.

Work on the strategically important scheme, led by BP, was halted in a region of Georgia in July while the government there sought assurances on “security” concerns. The underground “BTC” pipeline will take oil from Baku, in Azerbaijan, through the Georgian capital Tbilisi, to the port of Ceyhan in Turkey, from where it can be shipped to Western markets.

The US government has backed the 1,760km project as a way of accessing oil from important reserves under the Caspian Sea without it having to pass through Iran or Russia. The US has long sought to lessen the world’s dependence on oil from the politically unstable Middle East.

Construction along a 17.6km section of the pipeline that passes through the Borjomi region of Georgia was halted abruptly by the country’s environment ministry on 19 July. Work started again on Friday. BP, the single largest investor in the pipeline, is racing to complete the project during the first half of next year. Construction was only resumed after talks between Georgian leaders and high-ranking US officials, includingthe US Assistant Secretary of State, Elizabeth Jones, who visited Georgia unexpectedly last month.

The issue of the pipeline was a major topic in talks in Washington last week between Georgia’s president, Mikheil Saakashvili, and Mr Rumsfeld. Following his meeting with Mr Rumsfeld, the Georgian president said BP had “taken the first steps to satisfy the demands of the Georgian side”.

As well as fears that the pipeline would become a target for terrorists, the Georgian authorities are anxious about the effects that any leakages would have on the Borjomi region. The area is the source for mineral water. Georgian officials said BP had agreed to lay the pipe deeper under ground. The British company also agreed to additional measures above ground, with more security facilities and extra environmental safety technologies.

In her mission to Georgia last month, Ms Jones visited various sections of the pipeline. In a press briefing at the time, she said: “I am convinced of the environmental integrity and sanctity of the pipeline. The security issues involved with the pipeline are being taken care of.”

Some analysts believe that construction work on the BTC pipeline got caught up in Georgia’s wider strategic aims. According to one regional political commentator, Mubariz Ahmadoglu, the director of the Centre for Political Technology and Innovations, Georgia’s president was trying to use the threat to the BTC project to get the American government to intervene on Georgia’s behalf over the break-away province of South Ossetia.

Mr Saakashvili wants the US to put pressure on Russia to stop interfering in South Ossetia, and another separatist Georgian region, Abkhazia, which are ruled almost as if they were Russian territory. Abkhazia’s and South Ossetia’s “governments” have said they want to be annexed by Russia.

Mr Saakashvili discussedSouth Ossetia in his meeting with Mr Rumsfeld, Georgian officials said. Mr Saakashvili also held talks with Colin Powell, the US Secretary of State.