Statement on known Taliban website may indicate that leaders are retreating from alliance with al-Qaida

The Taliban have issued an English-language statement claiming they pose no international threat – a move that will fuel the debate among US and European policymakers over whether the hardline Afghan insurgent group can be split away from the international militants of al-Qaida.

The statement came amid reports that Barack Obama's military advisers are shifting the focus of US operations to target al-Qaida in Pakistan while downplaying the threat posed to America by the Taliban.

But 36 hours after the statement was released, the Taliban claimed responsibility for a massive suicide bomb targeting the Indian embassy in Kabul that killed at least 17 people.

Published yesterday on the eighth anniversary of the first coalition strikes on Afghanistan in 2001, the communique declared the militants' aim to be the "obtainment of independence and establishment of an Islamic system".

"We did not have any agenda to harm other countries including Europe nor we have such agenda today," said the statement, which was posted on a known Taliban website. "Still, if you want to turn the country of the proud and pious Afghans into a colony, then know that we have an unwavering determination and have braced for a prolonged war."

The statement's authenticity is yet to be confirmed, but the claim would appear to be evidence at the very least that the Taliban are seeking to influence the strategic argument in the west.

The statements may equally be a sign that senior Taliban figures are reassessing the movement's longstanding – but often tense – alliance with al-Qaida.

In a recent exchange of emails with the Guardian, a Taliban spokesman avoided questions on the relationship between the Afghan insurgents and Osama bin Laden. The spokesman said the Taliban closely monitored public opinion in western Europe and policy arguments in the US.

As Obama continues to reassess the Afghan war strategy, advisers told the New York Times that he had been presented with an approach that might not require the increase in troop numbers in Afghanistan called for by the most senior US and Nato general in the region, General Stanley McChrystal.

Obama will today meet the secretary of state, Hilary Clinton, and the vice-president, Joe Biden, who has been arguing for months that Pakistan is a greater priority than Afghanistan.

The New York Times said that Clinton and the defence secretary, Robert Gates, had warned that the Taliban in Afghanistan remained linked to al-Qaida and would give its fighters haven again if the Taliban regained control of all or large parts of Afghanistan.

"Clearly, al-Qaida is a threat not only to the US homeland and American interests abroad, but it has a murderous agenda," one senior administration official said. "We want to destroy its leadership, its infrastructure and its capability."

The official contrasted that with the Taliban, which the administration has begun to define as an indigenous group that aspires to reclaim territory and rule the country, but does not express ambitions of attacking the US. "When the two [groups] are aligned it's mainly on the tactical front," the official said, adding that al-Qaida had fewer than 100 fighters in Afghanistan.

Yesterday, the White House confirmed that Obama received McChrystal's troop reinforcements request a week ago. It is said to include a range of options, from adding as few as 10,000 additional combat troops to McChrystal's strong preference for as many as 40,000.

The renewed attention on Pakistan comes amid a recognition that the US can neither win the eight-year-old conflict in Afghanistan nor succeed more broadly against al-Qaida without help from Islamabad.

Obama and some of his key aides are increasingly pointing to recent successes against al-Qaida through targeted missile strikes and raids in Pakistan, Somalia and elsewhere. Obama said on Tuesday that al-Qaida had "lost operational capacity" as a result.

Serious doubts about the Afghan government have led some to question whether an effective counterinsurgency mission is possible.

McChrystal's recommended approach calls for additional troops in Afghanistan for a counterinsurgency campaign to defeat the Taliban, build up the central government and deny al-Qaida its refuge.

McChrystal, whose plan is reminiscent of Bush's troop "surge" in Iraq in 2008, says extra troops are crucial to turn around a war that probably will be won or lost during the next 12 months.

At the opposite end of the spectrum, an alternative favoured most prominently by Biden would keep the American force in Afghanistan at around the 68,000 already authorised, including the 21,000 more troops Obama ordered this year, but increase the use of surgical strikes with Predator drones and special forces.