The US dollar has declined to its lowest level in four weeks against the yen today (September 30th).
Fears regarding the potential shutdown of the US government have caused investors to turn to less risky assets.
The yen is traditionally seen as a safe haven in forex trading markets as Japan does not rely on foreign capital to fund its deficits and so is less exposed to external issues.
Congress has reached something of a stalemate, with Republicans demanding concessions in the Patient Protection and Affordable Care Act before they will agree to a federal budget for the new fiscal year, which begins at midnight.
If the deadlock cannot be broken before this time, all non-essential government employees will be sent home. This would be the first such shutdown in 17 years and it is estimated that around 1.4 percentage points could be removed from the country's gross domestic product output in the fourth quarter of the year.
As of 10:30 BST, the greenback was trading 0.34 per cent lower for the session at 97.91 yen.
