BEIJING, March 30 (Xinhua) -- China has called for a balanced and comprehensive deal on the Iranian nuclear issue at the earliest possible date, Foreign Ministry Spokeswoman Hua Chunying said here Monday.

Hua told a daily press briefing that the negotiation on the Iranian nuclear issue is making major progress.

The Chinese side hopes that all parties will seize the opportunity to push for a breakthrough in the current round and reach a just, balanced, mutually beneficial and comprehensive agreement on the earliest possible date, she said.

As one of six parties involved, China maintains an active and constructive position, working for a comprehensive, long-term solution, she said.

Chinese Foreign Minister Wang Yi has flown to Switzerland to attend a foreign ministers meeting on the issue.

As the March 31 deadline approaches, delegates continued intensive negotiations to pave way for the final resolution.

The Russian, Chinese and British foreign ministers joined the negotiations on Sunday, following French and German foreign ministers' Saturday arrival in the Swiss city of Lausanne.

During a one-hour bilateral talks with Iranian Foreign Minister Mohammad Javad Zarif, Wang Yi called for flexibility and strong political will.

All parties seem to agree that reaching an understanding by the end of March is crucial to signing a final agreement by the June 30 deadline.

According to a senior diplomatic source, key sticking points at this point include the details of when and how the lifting of UN and bilateral sanctions should be arranged in return for Iran's assurance to curb nuclear-related activities.

Iran's nuclear research, development ambitions and its nuclear enriching facilities also remain a critical dispute.

By Xinhua