WASHINGTON/NEW YORK: The United Nations cannot get enough cash into Afghanistan to deliver humanitarian aid to millions of people on the brink of starvation and is struggling to develop options to help stabilize the collapsing economy, U.N. officials said.

Ultimately political solutions are needed, a senior U.N. official told Reuters on condition of anonymity, an apparent reference to sanctions relief and for governments and institutions to free up billions of dollars of Afghan assets held overseas.

In the meantime U.N. agencies are scrambling to find ways to get large amounts of U.S. dollars into Afghanistan to combat a liquidity crisis that has taken hold since the Taliban ousted the Western-backed government in August. The U.N. official shared with Reuters some of the options being suggested.

The delivery of U.S. dollars to Afghanistan has stopped since the Islamist militants seized power and if countries or international financial institutions don't step up then the United Nations might have to fill the gap, said the official.

One suggested option is using Afghanistan International Bank, which could bring in and store money, but there are issues with insurance, the U.N. official said.