Greek Minister Demetrios Sicilianos arrives in DC to deliver down payment to repay US loan

The Greek Minister Siciliano discusses a payment involving a check for $75,000, which represents 40% of the interest due on Greece's post-war debt. He expresses gratitude to the United States government for accepting Greece's offer to pay this portion of the interest. Additionally, he mentions remitting a check to the US Treasury, representing the interest as per their agreement.

What was the amount represented by the check remitted to the United States Treasury?

What does the check represent in relation to the law mentioned by the Greek Minister?