Praising Jeremy Hunt, Johnson said he had been fond of his 'excellent ideas' and joked that he's planning to 'steal them.'
The United Kingdom has called Iran's actions to seize its tanker as "dangerous" and "illegal."
Owned by Swedish operator Stena Bulk, the tanker's crew of 23 consists of 18 Indians, three Russians, a Latvian and a Filipino.
UK foreign secretary Jeremy Hunt termed the seizure as "completely unacceptable" and stressed that "freedom of navigation must be maintained".
The European Union is desperately trying to prevent the deal unravelling completely, seeing it as the best way to stop Tehran acquiring atomic weapons.
Washington has pulled out of the deal, to the dismay of its European allies who also signed the accord.
The comments by Foreign Secretary Jeremy Hunt late Saturday could help de-escalate tensions that have spiked in recent days.
Conservative members are this month in the process of selecting a new party leader, who will almost certainly become prime minister, with the winner to be announced on July 23.
After several rounds of voting by Conservative lawmakers, Hunt and former London mayor Boris Johnson emerged as two main contenders.
Once a successor is confirmed, Theresa May would be expected to visit Queen Elizabeth II to formally tender her resignation as premier.
Next month Conservative Party members around the UK will choose the next leader of the Tory Party, who will be the next Prime Minister.
Tensions between India and Pakistan rose following the February 14 terror attack in Jammu and Kashmir's Pulwama district in which 40 CRPF soldiers were killed.
Speaking to reporters after meeting his Austrian counterpart Karin Kneissl, Hunt said: "At the moment we are heading for no deal by accident".
May was forced to carry out a reshuffle of her top team after Foreign Secretary Boris Johnson and Brexit Secretary David Davis both quit over differences with her over Brexit.