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.
23 de enero 2018
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|Guardiola: Quadruple-chasing City will only be judged on trophies|
|Karsiyaka and Nymburk reach FIBA Champions League last 16|
|Batshuayi out of chances to convince Conte|
|Chelsea lacked finances to compete with City & United for Sanchez - Conte|
|Sevilla 3 Atletico Madrid 1 (5-2 agg): Griezmann stunner not enough for semi spot|
|Bristol City 2 Manchester City 3 (3-5 agg): Guardiola through to first English final|
|Serena can return for more grand slam success – King|
|O´Neill signs Ireland extension|
|Teachers bowled over by Edmund ability|
|Woods grouped with Reed and Hoffman at Torrey Pines|
|New signing Jach sees Palace as platform for World Cup spot|
|Thomas replaces Sinckler in England training camp|
|Phil Neville appointed England Women´s manager|
|Heat unveil Miami Vice-themed uniforms|
|Kenedy leaves Chelsea for Newcastle loan|
|Wozniacki still haunted by 2011 Li Na loss|
|PSG rule out ´traumatic´ injury for Mbappe|
|PSG boost midfield options with surprise Diarra signing|
|Dyche commits to Burnley to 2022|
|Patriots elect to wear white in Super Bowl LII|
|Kobe Bryant´s ´Dear Basketball´ short film nominated for Oscar|
|Zidane tells Real Madrid fans to stop jeering Benzema|
|Players must manage their own schedules, says Cilic|
|Lucas Moura free to leave PSG, confirms Emery|
|Kenedy set for Newcastle as Conte waits for window to close|
|Bouchard agrees to another Super Bowl date|
|Neymar and Mbappe in doubt for PSG´s clash with Guingamp|
|Targeting the backhand, attacking the net and 83 winners: How Cilic subdued Nadal|
|Mascherano to leave Barcelona as Hebei move looms|
|Wozniacki reaches Australian Open semi-finals in early hours|
|Conte rules Morata and Fabregas out of Arsenal clash|
|Tamim and Shakib leave Zimbabwe facing tri-nation exit|
|Clarets snap up Lennon from Everton|
|Too many people are getting injured - Nadal frustrated by Aus Open retirement|
|Dzeko set to face Sampdoria despite Chelsea reports|
|It´s really unfortunate for Rafa - Cilic sympathises with injured Nadal|
|Zidane rejects suggestions he won ´battle´ over Kepa|
|Surprise semi-finalist Mertens ready for more Melbourne magic|
|Sorry Stars fail to shine again as Sixers claim consolation win|
|Injured Nadal bows out of Australian Open to Cilic|
|Ramos trains for Real Madrid as wounded Ronaldo works indoors|
|Wijnaldum admits Liverpool ´gave a half away´ against Swansea|
|I know what it feels like to be Andy Murray - Edmund revels in limelight|
|Wenger: Arsenal are about values, not millions|
|Gracious Dimitrov says Edmund deserved to win|
|Aubameyang to Arsenal not close, says Wenger|
|Hernandez open to West Ham exit|
|Superstar Sanchez will lift Manchester United squad, says Giggs|
|De Bruyne 2023: The sensational displays that won Manchester City´s talisman a new deal|
|How new recruit Sanchez compares to Manchester United´s forwards|
|Edmund claims shock win over Dimitrov to reach Aus Open semis|
|Cousins posts one of greatest stat lines in NBA history|
|Rockets close gap on Warriors by beating Heat|
|Lucas ´not happy´ at PSG|
|Svitolina reveals hip injury struggles|
|´Dangerous´ Cilic can beat Nadal, says Philippoussis|
|Mertens stuns Svitolina in Melbourne|
|Stones: Quadruple chase will take its toll on City|
|Klopp sorry for fan confrontation|
|Cowboys VP Jones calls out Bryant for sideline eruptions|
|Durant: Capela talking trash because of his easy role with Rockets|
|Buffon guaranteed to start on Juventus return, assures Allegri|
|Philander hails ´phenomenal talent´ Ngidi|
|Stokes to join England squad after court appearance|
|Giants hire Shurmur as next head coach|
|Liverpool´s win over City feels like six months ago for Klopp|
22 de enero 2018
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|Smith unconvinced by Kohli leadership|
|Swansea City 1 Liverpool 0: Mawson ends Reds´ unbeaten run|