Foreign Secretary David Cameron has threatened to withdraw co-operation with Scottish ministers after Humza Yousaf met with Recep Tayyip Erdogan.
The first minister met the Turkish president at COP28 without a UK official present, which Lord Cameron said was a breach of protocol.
It comes amid ongoing tensions between Scotland and the UK government over meetings with foreign officials.
A spokesperson for Mr Yousaf said a UK official was invited to the meeting.
Meanwhile a UK government source told the BBC Lord Cameron wants to take a “harder line” approach than his predecessor James Cleverly.
Foreign affairs are reserved to the UK government but the devolved nations are allowed to engage internationally on devolved competencies.
The BBC has seen a letter which Lord Cameron, who returned to the cabinet as foreign secretary last month, has written to the SNP’s External Affairs Secretary Angus Robertson.
In that letter, Lord Cameron said the Scottish government had assured the Foreign, Commonwealth and Development Office (FCDO) that it would give “sufficient advance notice” of the meeting with Mr Erdogan.
He said this was to allow one of his officials to attend the meeting and “was not done”.
“The absence of an FCDO official at this meeting contravenes the protocols in our guidance on FCDO support to devolved government ministers’ overseas visits,” the letter reads.
“Any further breaches of the protocol of ministerial meetings have a FCDO official present will result in no further FCDO facilitation of meetings or logistical support.
“We will also need to consider the presence of Scottish government offices in UK government posts.”
James Cleverly made a similar threat when he was foreign secretary after Mr Yousaf met the Icelandic prime minister in August, again without UK diplomats.
However a UK government source said this latest intervention represents and “escalation” over the issue and the foreign secretary wishes to take a “harder line” approach than Mr Cleverly.
On the meeting with President Erdogan, the source said that Foreign Office officials were not told where it would take place “until it was too late”.
The move “undermined UK foreign policy”, they said.
A UK government spokesperson added: “Foreign affairs is reserved under the Scotland Act and in such turbulent times, the need for the UK to speak on the world stage with one consistent voice is more important than ever.”
A spokesperson for the first minister said a UK official was aware of and invited to the meeting, and that the same arrangements were in place for Mr Yousaf’s engagements with other world leaders.
They added: “The nature of events such as COP is that timings can change at the last minute, and the FCDO representative was elsewhere at the time it was convenient for the Turkish president to meet.
“Any threat by the UK government to curtail the Scottish Government’s international engagement is misguided and would work against Scotland’s interests.”
A Scottish government source said Lord Cameron’s letter was a “gross overreaction”, adding: “You can hardly say to a president, ‘Can you wait a second while we find our chaperone?'”
They said that the FCDO representative was “very late” for a couple of meetings at the summit, but that was “the nature of fast moving things like Cop.”
The meeting between Mr Yousaf and Mr Erdogan had already proven controversial within the first minister’s party.
SNP councillor Roza Salih said she was “disgusted” by the meeting, as Turkey had stepped up attacks on Kurdish groups in Syria.
The Kurdish-born politician was elected in 2022 and became the first councillor to have moved to Scotland as a refugee.
An immediate & permanent ceasefire is needed now.
Too many innocent children have died, it must stop. pic.twitter.com/tDvs8X4tyJ
— Humza Yousaf (@HumzaYousaf) December 1, 2023
The first minister posted on X, formerly Twitter, that he had discussed the climate crisis and the Israel-Gaza conflict with Mr Erdogan and the Lebanese prime minister during their meeting on 1 December.
He said he had called for an immediate ceasefire in the region. The BBC understands this contradiction of the UK government position has caused particular concern in the foreign office.
Mr Erdogan has taken a critical stance of Israel, accusing it of behaving like a “war criminal”.
He made the comments while addressing thousands of demonstrators at a pro-Palestinian rally in Istanbul in October.
Israeli Foreign Minister Eli Cohen responded by ordering diplomats to return.
Prime Minister Benjamin Netanyahu said Israel has “the most moral army in the world”.