Iran has slammed Saudi Arabian Crown Prince Mohammed bin Salman after his statement over possible war with Tehran in 10-15 years.

"This delusional novice, who is still too big for his boots, either does not know what war is, or has not studied history or unfortunately has not talked to a venerable person," Iran's Foreign Ministry spokesperson Bahram Qassemi was quoted by Iranian media as saying, as reported by Al-Jazeera.

Saudi Crown Prince Salman called on the international community to create more pressure on the Iranian regime to avoid a military conflict, in an interview with the Wall Street Journal.

"We must achieve this in order to avoid a military conflict; if we fail to do this, we will probably have a war with Iran in 10-15 years," the prince said.

Earlier, Saudi Arabia called the 2015 nuclear deal between Iran and world powers a "flawed agreement" on the eve of a meeting between the Saudi crown prince and U.S. President Donald Trump who have both been highly critical of Iran. With Trump warning of a last chance for "the worst deal ever negotiated," Britain, France and Germany are working on a plan to satisfy him by addressing Iran's ballistic missile tests and its regional influence while preserving the 2015 accord.

Saudi Foreign Minister Adel al-Jubeir called out Iran for what Riyadh has long slammed as Tehran's destabilizing behavior in the region. "We've called for tougher policies towards Iran for years," he said.

Iran and Saudi Arabia are archrivals that back opposing sides in regional conflicts from Yemen to Syria.

A missile attack last week on Riyadh has raised the risk of an escalation in the Yemen war in a region riven with interwoven conflicts between the two countries. Yemen's war fits into a broader decades-long struggle for supremacy between Middle East powerhouses Iran and Saudi Arabia, which fund and train proxy forces in Iraq, Syria and Lebanon and accuse each other of backing terrorism.