Washington, Jul 14 (IANS): Negotiators have made "genuine progress" in the ongoing talks on Iran's nuclear programme, but some sticking points remain unsolved, the White House said on Monday.

"There have been some key issues in the negotiations that have been closed, and that's a good sign," White House spokesperson Josh Earnest told a press briefing, Xinhua reported.

After more than two weeks of bargaining in Austria's capital Vienna, Iran and the six major world powers are heading toward a deal to terminate the decade-old standoff over Iran's nuclear programme.

The talks have missed the previous deadlines of June 30 and July 7, and is set to miss the Monday deadline as some tough issues remain unresolved.

The main contentious issues include the United Nation's arms embargo on Iran, implementation of the international community's supervision over Iran's nuclear program and the pace of sanctions relief.

Iran has insisted on lifting all sanctions, including a UN embargo of conventional weapons. However, Western powers are reluctant to give in on the issue, voicing concerns that missiles could be used to deliver nuclear war heads.

US President Barack Obama had directed his team to remain engaged and participate in conversations "as long as those conversations remain useful," according to Earnest.