TEHRAN, March 5 -- Nuclear agreement is possible only if the imposed sanctions against the country is lifted all at once, senior Iranian nuclear negotiator Abbas Araqchi said on Thursday.

"Our principle position is that all sanctions are lifted at once," Araqchi, also Iran's Deputy Foreign Minister for Legal and International Affairs, told Press TV following the talks between representatives from Iran and the P5+1 group -- Britain, China, France, Russia, the United States plus Germany -- in the Swiss city of Montreux.

Lifting the sanctions is a "very important feature" of the talks and no sanctions should remain in place if the world powers are serious about a deal with Iran, he said.

The world powers should decide between achieving a deal and continuing to pressure Iran through sanctions, he said.

Iran and the world powers are trying their best to reach a sort of understanding by the end of March although major issues still remain to be resolved, he added.

Senior diplomats from the P5+1 group and Iran concluded their one-day negotiations in Montreux on Thursday aiming to find a final and comprehensive deal on Iran's nuclear program.

Earlier this week, U.S. Secretary of State John Kerry held a three-day discussion with his Iranian counterpart Mohammad Javad Zarif in Montreux, and then headed to Saudi Arabia on Wednesday to speak with Persian Gulf member states on the same issue.

The last round of nuclear talks between the P5+1 group and Iran was held some two weeks ago in Geneva.

Under an interim deal inked in November, 2013, Iran said it would suspend critical nuclear activities in return for a limited ease of sanctions.

After missing self-imposed deadlines twice, the negotiators agreed in November 2014 to extend the deadline for another seven months, hoping to reach a deal, which could be one of the most important and divisive international agreements in decades. Enditem