Reapply in case of lost visa :: Application requires more administrative processing

I had my B1/B2 visa interview yesterday. I have been travelling to United States since 2015 but had to re-apply as I lost my passport with a valid USA visa earlier this year. After interview my passport has been kept by the visa officer and he handed me over a letter which says " Your application required additional administrative processing. The application will be reconsidered when administrative process is complete".
Any suggestions are appreciated.
Many thanks!