Graeme Pitkethly said Kraft's offer had highlighted the importance of achieving a balance between long-term sustainable value, which it had prioritized, and short-term delivery.
"This has certainly been a trigger moment for Unilever, and we will not waste it," he said at the Consumer Analyst Group of New York conference in Boca Raton, Florida, in a presentation streamed on its website.
The U.S. company walked away from a fight with Unilever on Sunday, just two days after its $143 billion bid - and Unilever's rejection - was made public.
Kraft, which is backed by Warren Buffett and the private equity firm 3G, wanted to buy Unilever as part of its strategy to become a leading consumer goods giant by buying competitors and cutting costs and jobs to drive profits.
The approach caused Unilever, which makes OMO detergent and Magnum ice cream, to announce a far-reaching review on Wednesday, seeking to show shareholders it could realize the value spotted by its rival.
Pitkethly said he believed Unilever could do more to communicate the value buried within its existing plans, while the review would look at options for the group's portfolio, organization, cost structures, balance sheet and use of cash.
He said Kraft had taken advantage of a recent widening gap between Unilever's share price and the sector average, caused in part by a weak outlook for markets like India and Brazil.
"The combination of being at the bottom of the emerging market cycle combined with a lack of volume growth in the fourth quarter led to a very weak Unilever share price," he said.
"Add to this that we were at the bottom of credit cycle and our own strong balance sheet, and you have the opportunity for a leveraged offer."
Unilever, which has struggled recently amid slowing growth and currency fluctuations, saw its shares tumble 4.5 percent on Jan. 26, its worst day in nearly a year, when the company reported lower-than-expected fourth-quarter sales.
Kraft seized the opportunity to make an approach pitched at $50 a share, representing a premium of 18 percent.
Pitkethly said for most of the last year, a $50-a-share bid would have represented a premium of about 10 percent.
Unilever's shares jumped to an all-time high of 38.48 pounds when the approach was made public, and they have retained most of that gain, supported by Unilever's review and an upgrade to its guidance.
The shares were trading up 0.2 percent at 37.73 pounds ($47.14) at 1534 GMT on Friday.
Pitkethly said the bid "substantially undervalued" Unilever, while Kraft's approach to shareholder value was diametrically opposed to its own.
While Unilever had an "inherently sustainable" model of looking to grow by compounding returns and investment over the long term, Kraft, he said, relied on leverage to generate stronger short-term growth and earnings.
But without the foundation of strong organic growth, Kraft would be dependent on further deals.
"It may be there was a strong strategic rational for Kraft in combining with Unilever, but there was no strategic rationale for Unilever," he said.
($1 = 0.8004 pounds)
Reporting by Paul Sandle in London and Siddharth Cavale in Bangaluru; Editing by Kate Holton and Alexander Smith