© Agence France Presse/Getty ImagesFighters with the Free Syria Army are shown at an undisclosed location on Thursday.
Saudi Arabian officials will pay the salaries of the Free Syria Army in order to encourage mass military defections and increase pressure on the regime of President Bashar al-Assad's, the Guardian of London newspaper reported Friday.

The move has been discussed by Riyadh with senior U.S. and Arab world officials, the Guardian said.

The Guardian did not specify sources for its report. However, it said, Sen. Joe Lieberman, I-Conn., an active supporter of the Syrian opposition, recently endorsed the idea of ensuring pay for armed Syrian opposition, though not necessarily with U.S funds.

The plan is gaining support as weapons sent recently to rebel forces by Saudi Arabia and Qatar make a difference on battlefields in Syria.

Saudi officials embraced the pay idea when it [was] suggested by Arab officials in May, sources in three Arab states told the Guardian.

At that time, weapons started to flow across the southern Turkish border to Free Syria Army leaders, the Guardian said.

Turkey also allowed the establishment of an Istanbul command center staffed by 22 people, mostly Syrian, to coordinate supply lines in consultation with rebel army leaders inside Syria, the newspaper reported.

News of the pay plan emerged as international mediator Kofi Annan said Friday that Iran, an ally and neighbor of Syria, must be part of any solution to end the crisis in Syria and pave the way for a political transition.

The United States and Russia are in a standoff over Syria and Iran's nuclear program.

Annan wants the five permanent members of the U.N. Security Council and governments with influence on Syria's government or the opposition to agree on recommendations for next steps at a meeting that has been penciled in for June 30 in Geneva.

Iran's involvement is opposed by the United States, Britain and France, but Annan said it should be at the table.

"We are discussing the composition and other aspects of the meeting, but I have made it quite clear that I believe Iran should be part of the solution," Annan told a news conference in Geneva.

In response to Annan's remarks, the U.S. State Department repeated its opposition to Iran taking part, saying Tehran was playing a "destructive" role in Syria.

This article includes reporting by Reuters.