Top US officials have grown frustrated over the resistance of some Middle East states to help shut the financial pipeline of terrorists, the New York Times reported on Sunday.

Internal State Department cables, obtained by WikiLeaks and made available to news organizations, indicate that millions of dollars are flowing to extremist groups, including Al Qaeda and the Taliban, despite US vows to cut off such funding, the report said.

A classified memo sent by US Secretary of State Hillary Clinton last December made it clear that residents of Saudi Arabia and its neighbors were the chief supporters of many extremist activities, the newspaper said.

It said that "donors in Saudi Arabia constitute the most significant source of funding to Sunni terrorist groups worldwide" and offered similarly critical views about other countries in the region.

The UAE was described as having a "strategic gap" that terrorists could exploit, while Qatar was seen as being "the worst in the region" on counter-terrorism and Kuwait was described as "a key transit point".

The publication of the leaked US embassy cables, which began late last month, has embarrassed Washington as well as foreign governments. Clinton has sharply criticised the leaks but said they will not harm important US alliances.

The cables cited by the Times detailed a long list of methods that suspected terrorists are using to finance their activities, including a bank robbery in Yemen last year, drug activity in Afghanistan and the annual pilgrimages.

One memo reported on a possible plot by Iranians to launder $5 billion to $10 billion through the UAE banks as part of a broader effort to "stir up trouble" among the Gulf states, the Times said.   

The Clinton cable stressed a need to "generate the political will necessary" to block money to terrorist networks -- groups she said were threatening stability in Pakistan and Afghanistan and targeting coalition soldiers, the Times said.

In private meetings foreign leaders have accused US officials of pursuing Arab charities and individuals in a heavy-handed manner and on thin evidence. - Reuters