Interim Friday prayer leader of Tehran hailed bravery and trustworthiness of Iranian nuclear negotiators enumerating oil export and removal of sanctions as important issues to be discussed in the talks.

Ayatollah Seyyed Ahmad Khatami, interim Friday prayer leader of Tehran, in his weekly sermon in the Iranian capital of Tehran, spoke about the ongoing JCPOA talks in Vienna aimed at removing anti-Iran sanctions.

Oil export and the removal of sanctions play an important role in these negotiations, Khatami said, adding that of course, Iran can do this (oil export) without the removal of the sanctions.

He went on to say, "Although we have no problem with negotiations, nevertheless, we must bear in mind that the US is our biggest enemy."

Washington's problem is not about Iran's nuclear program, but it is about the principle of the system of the Islamic Republic of Iran, he said.

He also quoted an American theoretician as saying that US' main problem is that Iran has become the biggest scientific power in the region.

The senior cleric also said that Iranian negotiators are trustworthy and brave enough so that they will not give concessions to the enemy.