The Borussia Monchengladbach striker joined the Magpies on Wednesday on a deal until the end of the season.
Newcastle have the option to make the 23-year-old's switch permanent in the summer.
"We're delighted to bring Luuk de Jong to the club," Kinnear told United's official website. "He has an excellent pedigree and will add significantly to our striking options.
"We've been watching him for a little while now and I am sure he will prove to be a valuable acquisition for us."
De Jong is available for Saturday's derby between Newcastle and Sunderland in the Premier League.