The short answer? No.
Since the ESTA (Electronic System for Travel Authorization) is not a visa, but is a travel authorization for citizens of the US visa waiver program (VWP), it only needs to be valid on the day you travel to the United States.
You do not need to renew it while you are in the US, even if it expires before you depart.
Countries that are part of the VWP include:
|Czech Republic||Liechtenstein||South Korea|
For more information on applying for ESTA from the official website, please see our previous blog: Don’t pay more than 15 euros for an ESTA!