NEW YORK General David Petraeus, the commander of the US forces stationed in Afghanistan, issued a veiled warning to Pakistan that his country could launch ground operations in Fata, if Islamabad refused to dismantle the militant network in North Waziristan. A top American newspaper said the warning was an evidence of the growing frustration of the US officials who believed that Pakistani Army was unlikely to launch a military operation in the belt, suspected by Western intelligence to be a haven for Al-Qaeda and Taliban operatives. Petraeus wants to turn up the heat on the safe havens, a senior American official was quoted as saying by The New York Times, a reason why the US forces had sharply stepped up drone strikes in the area. He has pointed out to the Pakistanis that they could do more, he added. Special operations commanders have also been updating plans for cross-border raids, which would require approval from President Barack Obama. Meanwhile, CIA has stepped up its unmanned aerial bombing campaign in Pakistan to thwart Taliban insurgents, the US officials said. CIA initiated 20 attacks with armed drones so far in September, as top officials work to stem the rise of US casualties before the Obama Administrations review of its Afghanistan strategy in December, The New York Times. The US and European officials also are assessing reports of possible terrorist activities in the west from militants based in Pakistan. The war along the Afghanistan-Pakistan bordering region is picking up in other ways, as three air strikes into Pakistan, according to US military officials estimate, killed more than 50 suspected members of the Haqqani network. Pakistani officials have criticised the attacks, saying that NATOs mandate is to carry out attacks only in Afghanistan. The terror plot is believed to target several countries, including Britain, France and Germany, officials told The Wall Street Journal. The exact nature of the threat hasnt been determined. There are some pretty notable threat streams, one US military official said.