Kneissl, whose country did not follow UK’s lead, said in a show on Austria’s ORF television channel it was important to keep channels for dialogue open.
"One is asked to mediate. But we are a go-to partner for all those involved," she said. "If we are asked to we will certainly step in."
Seventeen EU nations agreed earlier this week to expel Russian diplomats in a show of solidarity with the United Kingdom after it blamed Russia for the March 4 poisoning of an ex-spy and his daughter.
An opportunity for Austria's mediation will arise on June 13 when its Chancellor Sebastian Kurz will travel to London for talks with UK Prime Minister Theresa May, the diplomat added.