Leader of the Islamic Revolution of Iran Grand Ayatollah Sayyed Ali Khamenei said on Tuesday that recent remarks by US officials are “totally a cause for suspicion."

Leader of the Islamic Revolution of Iran Grand Ayatollah Sayyed Ali Khamenei said on Tuesday that recent remarks by US officials - that came after official implementation of a nuclear accord and lifting of sanctions on Iran - are “totally a cause for suspicion."

In a letter to President Sheikh Hassan Rouhani answering his thanks for Leader's support, Ayatollah Khamenei stated that the achievements of nuclear talks are a result of resistance, urging the Iranian government “to be aware of the other party's fulfillment of its obligations” under the nuclear accord which went into force on Saturday.

The leader said he was pleased that parts of oppressive sanctions against Iran have been lifted and certain sides of talks who are known for their hostility towards Iran have been made to retreat from their previous positions.

Reiterating that any achievement gained against the arrogant and bullying front has been the result of the Iranian nation's resistance, he warned the government to be vigilant about deceitful measures and breach of undertakings by the arrogant governments, especially the United States.

His eminence called the outcome of nuclear talks as the result of Iranian nation's resistance against oppressive sanctions and also due to the efforts of Iranian nuclear scientists who advanced this industry forward.

"Removal of sanctions alone will not resolve country's economic problems and government should do its best for implementation of Resistance Economy with good management and using internal capacities," Ayatollah Khamenei added.

The Leader said that in calculation of results of nuclear talks, the costs of reaching agreement with P5+1 should be considered and explained to Iranian people honestly.

"The achievements of nuclear talks are the result of resistance towards arrogant powers and this is a lesson for all of us," he noted.

Moreover, Ayatollah Khamenei hailed result of nuclear talks and thanked the nuclear negotiating team for their sustained efforts.

On Saturday, Iranian Foreign Minister Mohammad Javad Zarif and European Union foreign policy chief Federica Mogherini read out a joint statement in Vienna, capital city of Austria, which ended the long process of nuclear talks between Iran and six world powers and started the implementation phase of the deal.

US officials have stepped up their anti-Iran rhetoric, accusing Tehran of posing a “threat to regional and global security” after Washington announced new sanctions over Iran’s ballistic-missile program.