Vettel had earlier announced that he will be leaving Ferrari at the end of current campaign and it was being speculated that he could form a dream team with six-time champion Hamilton at Mercedes at the expense of Bottas - who recently won the season-opening Austrian Grand Prix.
Kallenius has now said that the two Mercedes drivers have been performing at the highest level for a while now and there is no point in tinkering with the line-up.
"We're staying with our two boys,' Kallenius told Sky Sports Germany. "I can understand that this is a very exciting thought for the German fans.
"But with Lewis and Valtteri we already have two top drivers who perform at the highest level.
"We saw it with Valtteri taking pole (at Austrian GP) with a fantastic lap. We stand by the two drivers that we have now," he added.
It was team principal Toto Wolff's words last month that started speculations linking Vettel to Mercedes. He had said the the team was happy with the racers on their roster but in case the situation changes, they could look at Vettel.
"Sebastian is a four-time world champion and him suddenly becoming available was unexpected. And, therefore, it is a situation that needs to be monitored," Wolff had said during Sky F1 Vodcast as per Fox Sports.
"Where could he potentially go, where are we with our drivers, and what I said (before) is I wouldn't discount Sebastian for any seat.
"We have looked at the situation. Our priority and concentration is on our Mercedes drivers - that's Lewis (Hamilton), Valtteri (Bottas) and the juniors.
"And only if we can't find a solution within that group of drivers we will look elsewhere and then obviously Sebastian is in a very good position," he had added.
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