Iran's supreme leader on Saturday backed President Hassan Rouhani's overtures to the West but criticised some aspects of a UN visit during which he held talks with US counterpart Barack Obama.
The comments were the first public response by Ayatollah Ali Khamenei, who wields ultimate authority in Iran, to Rouhani's opening to the West in New York last week that was capped by the historic 15-minute telephone conversation with Obama.
"We support the diplomatic initiative of the government and attach importance to its activities in this trip," Khamenei told military commanders and graduating cadets in remarks reported by his website, Khamenei.ir.
However, he added -- without elaborating -- that "some of what happened in the New York trip was not appropriate... although we trust in our officials."
The September 27 telephone conversation, the first diplomatic contact between Iranian and US presidents, broke 34 years of icy relations between Washington and Tehran since its 1979 Islamic revolution.
For Khamenei, who has the final say on all matters of state including foreign policy, suspicions run deep.
"We are pessimistic towards the Americans and do not put any trust in them. The American government is untrustworthy, supercilious and unreasonable, and breaks its promises," he said.
For Saeed Leylaz, a Tehran-based pro-reform political commentator, Khamenei's criticism should not overshadow the new softer tone in Iran's foreign policy.
"Even if the supreme leader is critical, one should not forget that without his permission the diplomatic initiative would not have been put in action in the first place," Leylaz told AFP.
Rouhani's visit to New York for the UN General Assembly came after Khamenei had given the government permission to show "heroic flexibility", raising Western hopes of a breakthrough in long-stalled talks on Iran's controversial nuclear programme.
"Heroic flexibility is very useful and necessary sometimes but with adherence to one main condition," Khamenei told members of the elite Revolutionary Guards on September 17.
"A wrestler sometimes shows flexibility for technical reasons. But he does not forget about his opponent nor about his main objective," he said at the time.
There has also been public criticism of the Rouhani-Obama phone conversation from the Guards, whose commander General Mohammad Ali Jafari said on Monday the Iranian president should have waited for US concessions before agreeing to the call.
Leylaz said the opposition of hardliners to any speedy rapprochement with the West was understandable, given deep-running hostility towards the US and that "there are domestic politics in play as well."
But Khamenei's support for the government's diplomatic gestures falls "in line with a change to the Islamic republic's uncompromising position on foreign policy," he added.
In addition to Rouhani's phone call, Foreign Minister Mohammad Javad Zarif met US Secretary of State John Kerry in New York for talks between Iran and the major powers on its nuclear programme.
Rouhani has vowed to take a more constructive approach to the talks in a bid to win relief from crippling US and European Union sanctions on Iran's oil and banking sectors.
Representatives of Iran and the six powers are to meet in Geneva later this month to seek ways to jumpstart decade-old negotiations that were put on hold in April ahead of the presidential election in which Rouhani won a surprise first-round victory.
'Repetitive and disgusting threats'
Khamenei on Saturday also hit out at Washington for its alliance with Iran's number one foe, Israel.
The American administration "is a government that is seized by the international network of Zionism, and has to put up with the usurper (Israeli) regime and show flexibility towards it," Khamenei said.
Israeli Prime Minister Benjamin Netanyahu secured a tougher line from Obama in his public comments after their White House talks last Monday, sparking Iranian accusations of "flip-flop" by the US president.
Obama said Rouhani's overtures would be judged on actions and not words, adding that the use of military force was still on the table.
In his address to the General Assembly last Tuesday, Netanyahu warned that Israel was ready to act alone in taking military action to prevent any possibility of Iran developing a nuclear weapons capability.
Khamenei said any such action would be met with a "harsh" response.
"We hear the repetitive and disgusting threats of the Iranian nation's enemies. Our response to any mischief will be serious and harsh," he said.
Iran has warned in the past that any attack against its soil would provoke retaliation against the Jewish state and against US bases and warships in the region.