"Together, we can advance our shared vision of a healthier, more-sustainable planet", she said.
Israel-based Sodastream makes a machine and refillable cylinders allowing users to make their own carbonated drinks.
Under the cash deal, PepsiCo is to pay US$144 a share for the fizzy water makers outstanding stock, a premium of 11 per cent over its closing price on Friday.
Monday's sale looks to inject another big tax payout to Israel following previous the sales of Israeli companies such as the mobile navigation app Waze, which was acquired by Google for about $1 billion United States, and Mobileye, which produces technology for self-driving cars and was gobbled up by Intel past year for $15 billion US.
"With sugary carbonates and juices struggling and no turnaround in sight, mitigating the losses through newer and healthier products will be essential for PepsiCo", said Euromonitor International analyst Matthew Barry.
SodaStream, which is listed on the NY and Tel Aviv stock exchanges, has not been immune to the complex politics in its home region.
PepsiCo said SodaStream complements its water business, which includes Aquafina and smaller brands Bubly and Lifewtr.
The acquisition has been unanimously approved by the Boards of Directors of both companies.
If regulators approve the deal, it is expected to be finalised by January 2019, subject to a vote by Sodastream shareholders.
The buyout offer is "validation of our mission to bring healthy, convenient and environmentally friendly beverage solutions to consumers around the world", Daniel Birnbaum, SodaStream chief executive said in a statement.
SodaStream shares have jumped 49 per cent this month after the company boosted its forecast for revenue growth this year to 23 per cent and reported first-half figures that beat estimates. SodaStream faced calls for a boycott several years ago over a factory it had in the West Bank, despite employing many Palestinians. PepsiCo was advised by Goldman Sachs and Centerview, while SodaStream was advised by Perella Weinberg Partners.