TEHRAN - The United States should seize the opportunity for a nuclear deal with Iran, otherwise Iran is ready to expand its nuclear program, Iranian Students' News Agency quoted an Iranian official as saying on Sunday.

"The United States can not threaten Iran with military attacks or increase sanctions against Tehran, and they have no choice but negotiations," said Mohsen Rezaei, the secretary of Iran's Expediency Discernment Council and the former commander of Iran's Revolution Guards Corps.

The U.S. has geared the ongoing nuclear talks to Iran's missile capability and asked Iran to limit its missiles' ranges to 300 km,

which means to disarm Iran in the face of Israeli threats, he said.

"This shows that the U.S. officials want to impose a war on Iran in the future... they are making mistakes and sending suspicious signals to (ongoing nuclear) negotiation table," he was quoted as saying.

Rezaei hailed what he called "prudence, bravery and resistance" of Iranian negotiating team in the talks, urging the U.S. officials "to seize the opportunity of President Hassan Rouhani's smiling gestures" to settle Iran's nuclear issue diplomatically.

If the United States fails to reach an agreement with Iran for a nuclear deal and poses irrelevant demands in the nuclear talks, Iran is ready to increase the number of its uranium enrichment centrifuges to 100,000, according to the report.

Since 2013 when Iran entered negotiations with the P5+1 group - - including the five permanent members of the UN Security Council,

plus Germany -- to resolve the disputes over its nuclear program,

the Iranian top officials said defense capabilities and missile program of the country would not be included in the talks as it is the redline for Tehran.

However, West recently raised the issue of Iranian missiles as a sticking point in a run for a comprehensive nuclear deal. Tehran reiterated its previous stance, saying that its missile program is separate issue and irrelevant to the nuclear talks.

On Saturday, U.S. Secretary of State John Kerry said in the Austrian capital of Vienna that difficult issues remain on the Iranian nuclear talks and they still need to be resolved.

Talks between Iran and world's major powers were extended into another overtime by Monday after missing the deadlines of June 30, July 7 and July 9.

Foreign ministers from the P5+1 group will rejoin the talks on Sunday.