Iran’s Supreme Leader, Ayatollah Ali Khamenei, on Saturday lauded President Hassan Rouhani’s recent diplomatic efforts and historic visit to the U.N. in late-September, but he criticized certain aspects of the president’s visit as “not fitting.”

"We support the government's diplomatic movements and place importance on diplomatic efforts, and [we] support what was in this last trip," Khamenei said while addressing military commanders and graduating cadets at a ceremony, the ISNA news agency reported.

"Of course, in our opinion, some of what occurred in the New York trip was not fitting," he said, without further elaboration.

The comments were Khamenei’s first public response to Rouhani’s landmark trip to the U.N. and 15-minute telephone conversation with U.S. President Barack Obama, which marked the first diplomatic contact between the heads of the two nations since 1979.

Rouhani’s recent overtures toward the West eased tensions between the Middle East nation and the U.S.

Iran is facing U.N. sanctions due to its alleged nuclear weapons program, but Tehran denies the allegations and claims that its nuclear program is peaceful. 

During his speech at the U.N., Rouhani had offered immediate negotiations aimed at removing any "reasonable concerns" over Iran’s nuclear program.

Rouhani’s call for a peaceful and diplomatic solution to the dispute over its nuclear program was opposed by hard liners in his country.

Khamenei, a top Shia cleric, wields ultimate control in the country and holds final say on all domestic and foreign policy-related matters. Khamenei's broad support for the diplomatic efforts could bolster Rouhani in his international negotiations with other countries on the nuclear issue. Those negotiations are planned for Oct. 15.

However, Khamenei expressed concern about trusting the U.S. government due to its close alliance with Israel.

"We are pessimistic toward the Americans and do not put any trust in them," he said.

"The American government is untrustworthy, supercilious and unreasonable, and [it] breaks its promises."