Helmut Marko has refused to rule out a move to Honda power for Red Bull at the end of the 2018 Formula One season, saying "everything is open".
Honda have endured a difficult time since returning to the sport with McLaren in 2015, managing two ninth-place finishes either side of ending the season sixth in the constructors' standings in 2016.
McLaren have partnered with Renault for the 2018 campaign, as Honda enter a new arrangement with Toro Rosso - Red Bull's sister team, who are also overseen by Marko.
In an interview on the F1 website, Marko was asked whether a successful partnership between Toro Rosso and Honda could lead to a future deal between the Japanese engine supplier and Red Bull.
"We are very happy with the Toro Rosso and Honda cooperation," he said. "Toro Rosso will put all its efforts into making a competitive chassis.
"We do believe in Honda - otherwise we wouldn't have made that deal. I am very impressed with the facilities that they have - and their determination to win.
"It is just a matter of bringing everything together and we believe that this moment will arrive sooner than everybody is expecting.
"We will observe very closely - beyond 2018, everything is open!"
Red Bull could be left with no option but to switch to Honda power for 2019 should they not extend their deal with Renault.
Ferrari and Mercedes are understood to have little appetite to add to their current supply commitments, leaving Honda as the only other manufacturer on the grid.
17 de diciembre 2018
|Canelo, Crawford, Lomachenko and the other pound-for-pound contenders|
|Barcelona boss Valverde admits to Lyon uncertainty|
|Club World Cup: Maverick Quintero gets another chance on the big stage|
|Henderson to miss majority of Ireland´s Six Nations campaign|
|Gentner to play on despite father´s death|
|Just good banter – Australia and India not concerned by Paine-Kohli exchange|
|Titans CB Logan Ryan out for season with broken leg|
|Suns send Trevor Ariza to Wizards for Kelly Oubre, Austin Rivers|
|Mourinho charge for ´improper´ language dismissed|
|Are the Knicks for sale? Depends on the offer, says Dolan|
|Klopp´s Liverpool are vulnerable – Neuer|
|Warrington: Frampton not an elite fighter|
|I want to finish the job off - Yates confirms Giro d´Italia focus in 2019|
|Atletico confirm Filipe Luis hamstring injury|
|Best backs Schmidt to lead Lions in 2021|
|Barcelona´s Vermaelen out for a month with calf injury|
|India lose Shaw for Australia tour as defeat looms in Perth|
|We didn´t have much luck - Nedved dismayed by Atletico tie|
|Manchester City must control Schalke, Begiristain warns|
|Ibrahimovic hints at LA Galaxy stay|
|Latham fills his boots in Wellington with record-breaking knock|
|I´m not thinking ´thank God it´s Bayern´ – Klopp|
|Luis Garcia and Steve McManaman confident of Liverpool progress|
|Arsenal face BATE as Chelsea get Malmo in Europa League|
|Europa League last 32: Draw in full|
|Irwin urges Mourinho turnaround before PSG Champions League clash|
|Rush backs German Klopp to see off Bayern|
|Hope shines as West Indies blitz Bangladesh in Sylhet|
|United and PSG set for Champions League showdown|
|Ajax star De Ligt delighted to join Golden Boy alumni|
|Champions League last 16: Draw in full|
|Lyon strikes to put Australia on course for victory in Perth|
|Mourinho´s players below Manchester United standards, says Giggs|
|We´ve got to find a way to get better in a hurry - McVay challenges spluttering Rams|
|Van Dijk hails ´game-changer´ Shaqiri for downing Man United|
|LeBron praises magical Wall as Lakers fall flat on the road|
|Champions League last 16: Who could get who in Monday´s draw?|
|Pochettino urges fans to ´kill´ racism ahead of EFL Cup derby|
|Ajax star De Ligt wins Golden Boy award|
|Foles fuels Eagles´ upset win over Rams|
|Latham carries bat as New Zealand leave Sri Lanka reeling|
|Keep your cool, Virat – Paine and Kohli in another confrontation|
|Depleted Nuggets complete season sweep of Raptors|
|Fabinho was ´outstanding´, says Klopp|
|Patriots QB Brady on loss to Steelers: We aren´t playing well enough to win|
|Elliott says Cowboys´ shut-out loss to Colts was embarrassing|
|De Bruyne not worried about Liverpool title challenge|
|Sixers star Simmons makes history with triple-double|
|WATCH: Nowitzki receives standing ovation in first home game of season|
|Seattle´s playoff spot on hold after Seahawks suffer OT loss to 49ers|
|Cheika survives as Wallabies coach, Johnson appointed|
|Vikings remain in NFC playoff picture|
|Steelers stay ahead as Patriots lose AFC´s second seed|
|Lionel Messi is the best, says Amor|
|I´m still tired just looking at Robertson – Mourinho in awe of Liverpool intensity|
|Casillas takes swipe at Mourinho after United lose to Liverpool|
|Valverde relieved as Messi brilliance prevents another Levante nightmare|
16 de diciembre 2018
|WATCH: Leno proposes to girlfriend after Bears clinch division title|
|Messi and Suarez the world´s best strike partnership, says Pique|
|Klopp: I cannot keep every Liverpool player happy|
|Messi and Suarez outscoring Real Madrid and Atletico in LaLiga|
|Levante 0 Barcelona 5: Marvellous Messi banishes ghosts of last season|
|Colts rout Cowboys to keep playoff hopes alive|
|Bears shake off Packers to win NFC North and return to playoffs|
|Mourinho explains Pogba omission and defends Lukaku´s Liverpool showing|
|Liverpool´s display against Manchester United one of the best, claims Klopp|
|Look away Jose! Damning stats expose Manchester United´s limp Liverpool loss|
|Time´s up, Mourinho: Manchester United can dither no longer|
|Manchester United´s players are not dishonest – Mourinho|
|Manchester United´s lack of ambition under Mourinho is scary – Keane|