"The Islamic Republic of Iran has tried to resolve issues through negotiations, but it will stand up to the excessive demands of some western countries…," Velayati said in a meeting with officials of the China's Strategic Studies Center in Beijing on Wednesday.
Velayati is in China to attend a Conference on Interaction and Confidence Building Measures in Asia (CICA) in Beijing.
The top Iranian adviser reiterated that Iran will also seek the help of interested states to resist against the West's excessive demands.
Earlier today, Supreme Leader of the Islamic Revolution Ayatollah Seyyed Ali Khamenei urged the Iranian negotiators not to bow to the West's pressures and keep on insisting on the country's stances that have already been announced.
"The negotiators should insist on the stances that have been announced and I hope they could meet the country's and the ruling systems system's interests," Ayatollah Khamenei said in a meeting with Iranian Parliament Speaker Ali Larijani and parliamentarians in Tehran.
Yet, the Supreme Leader underlined that the Iranian negotiators are engaged in hard work and efforts.
"There are many solutions to the nuclear issue all of which rely on the domestic capacities and reinforcing (domestic) production," Ayatollah Khamenei added.
The Supreme Leader underlined that the nuclear issue is only a pretext to pressure Iran and even if this problem is resolved, the western powers would seek other excuses such as "human rights".
Ayatollah Khamenei called on the Iranian officials to rely on the country's domestic capabilities, and said, "If we boost production and use domestic potentialities, this will not only solve internal problems, but also facilitate settlement of foreign issues such as the nuclear one," Ayatollah Khamenei added.
After nine days of hard work in Lausanne, Switzerland, Iran and the Group 5+1 reached an understanding on April 2 which laid the ground for them to start drafting the final nuclear deal over Tehran's nuclear energy program ahead of a July 1 deadline.
Reading out a joint statement at a press conference with EU foreign policy chief Federica Mogherini in Lausanne on April 2, Zarif said according to the agreement, all the US, EU and UN Security Council sanctions against Iran would be lifted under the final deal.
The seven nations are now drafting the final deal.
But earlier this month, Head of the Atomic Energy Organization of Iran (AEOI) Ali Akbar Salehi complained that the world powers welsh on what they agree to undertake in the nuclear talks with Iran.
"We welcome interaction as Iran's logic is based interaction with the world. We are not after confrontation," Salehi said in Tehran, addressing a ceremony to commemorate the Iranian nuclear scientists assassinated by the foreign spy agencies.
He said the nuclear negotiations with the G5+1 are progressing well, but "they are lowballing with regard to certain issues that we had agreed on."
Salehi underscored that Tehran is after a nuclear agreement with the world powers "but not at any price".
His remarks came after the US Senate advanced a legislation that would allow the Congress to review a nuclear deal between world powers and Iran. The bill turned into a law by President Obama's endorsement.