Giorgio Cafiero said the quartet of nations – Saudi Arabia, Bahrain, United Arab Emirates and Egypt – are refusing to negotiate with Qatar over a long standing fued that has seen diplomatic and econmic links with Doha severed.
The US is currently backing moves by the Saudis to punish Qatar for allegedly funding the Muslim Brotherhood and other “radical Islamic terrorism”.
Former White House strategist Steve Bannon this week said the crisis in the Gulf was the single most important issue in the world – more so than the dispute between the US and North Korea.
Behind closed doors, senior Washington politicians are said to be fed up with the seige countries’ stance.
Writing for US foreign policy weblog LobeLog, Mr Cafiero said recent statements from Rex Tillerson’s US State Department are evidence of the US growing tired of the four nations’ stance against Doha.
Mr Tillerson recently said: “We cannot force talks upon people who aren’t ready to talk.
He cited a “real unwillingness” from the four countries to engage in roundtable talks, adding that “Qatar has been very clear they’re ready to engage”.
Saudi Arabia, the UAE, Bahrain and Egypt imposed an unprecedented land, sea and air blockade on their rich Gulf neighbour on June 5.
The dispute pits some of America’s closest Arab allies against one another and US diplomatic efforts to resolve the crisis have not been helped by US President Donald Trump’s apparent support for the blockade.
After Saudi Arabia and its allies announced the boycott, Mr Trump sent a tweet supporting the blockade and he later accused Doha of supporting terrorism “at a very high level”.
Mr Tillerson has tried to protect US interests by rowing back on Mr Trump’s apparent support for the boycott early on, although the Trump administration has sent conflicting messages about the crisis in the Gulf.
Qatar has rejected accusations that it supports extremists groups and signed a counter terrorism agreement with the US last month.
Qatari Foreign Minister Sheikh Mohamed bin Abdulrahman Al Thani said the countries behind the blockade have not yet provided evidence to back up accusations that Qatar supports terrorism.
He warned the blockade is harming global efforts against the Islamic State group.
He said: “We have seen continuing escalation and attempt to market the accusation that Qatar supports terrorism without providing any evidence.
“Unfortunately, this is their constant behaviour since the beginning of the crisis.”