There are signs that the launch would come soon rather than later.
Japan is the only country that has made explicit public plans to attempt to shoot down the North Korean rocket. The launch trajectory is expected to pass directly over northern Japanese territory.
Japan's defense minister ordered the country's self-defense forces last week to prepare to destroy any part of the rocket that looks like it may pose a threat.
A launch could occur 'any minute,' two sources told a news agency and likely not as late as Sunday.
The predictions of an early launch partly are based on the weather forecast in Pyongyang — and because the US would be less ready to monitor the launch the sooner it starts.
Obama said the planned launch has put 'enormous strains' on international talks over North Korea's disputed nuclear ambitions.