Following the departure of Romelu Lukaku to Chelsea, the Nerazzurri have been desperate to keep hold of the 24-year-old, who had been linked with a move to the Premier League this summer, with North London rivals Tottenham Hotspur and Arsenal believed to have expressed their interest.
Martinez will see his current contract expire in 2023, however Marotta has confirmed that the club are in direct negotiations with the Argentine to extend his deal.
"We're in well advanced talks to extend Lautaro Martinez's contract as with other players too. We're confident - there's no problem on contract situations", Marotta told Sky Sports News in Italy.
Marotta is also hopeful that the Scudetto champions can tie down Croatian duo Marcelo Brozovic and Ivan Perisic to new contracts, as their current deals expire next summer.
Martinez enjoyed an impressive campaign for Inter last season, scoring 19 goals and providing 11 assists in 48 appearances across all competitions.