senator bob corker has countered barack obama 's previous assertion .
he claims congressional oversight ` does n't mean there wo n't be a deal '
adds congressional scrutiny is vital to make sure deal is not bad one .
congress must ` tease out and ask important questions ' about the pact .
any nuclear agreement with iran must also be approved , corker says .
the deal , announced thursday , is scheduled to be finalized by june 30 .
senate foreign relations committee is due to meet april 14 to consider corker 's legislation to ensure congress debates and signs off any pact .