While USA has been restricted to the search operation of the plane, any deductions by the country linking the incident to terror attack has not been taken seriously.
In fact, there are just two FBI agents in Kuala Lumpur, who are hunting for clues leading to any terror links with the people on board.
However, "We just don't have the right to just take over the investigation," said a senior U.S. official who, like others, spoke on the condition of anonymity because the investigation was continuing. "There's not a whole lot we can do absent of a request from them for more help or a development that relates to information we may have," said one of the USA officials.
What USA believes
Although at a speculative stage, USA investigators have come up with circumstantial theories. Al-Qaida's Southeast Asian affiliate, for instance, had once discussed recruiting commercial pilots in Malaysia to crash a plane.
It could also be an act by members of China's Uighur minority, who may have targetted the plane as most of the passengers were Chinese. A lone-wolf attack by someone, without necessarily having ant ties with terrorist groups or someone with a troubled psychology have also not been ruled out.
What is puzzling both the US and the Malaysian authorities is that after the systems were switched off, it was hovering over the open sea for almost 7 hours.
And if this is a looming threat like that of 9/11 or if it was hijacked, then why were there no threat calls, claims or ransom calls by anyone.
Add to it the confusion over the time when the transponders and the ACARS were switched off-after the aircraft made its last contact with the ground staff or after that.
What USA did?
America has conducted an ink analysis, which is a computer-based investigative technique that tries to link individuals based on extensive and government reports; here it is between the pilots and the two passengers without passports. The country is also investigating the flight simulator that was found in the captains' house and US sources are awaiting results.
Despite that, an US FBI officials working out of Kuala Lumpur has said that Malaysia has turned down their offer for help as they did not want to appear to be needing help in such a high-profile incident. [Read more]