Hillary Clinton, the US secretary of state, has raised concerns over a move by the United Arab Emirates, a key US ally in the Gulf, to shut down a US-funded rights advocacy group.
"We very much regret it," Clinton said after a meeting in Riyadh, Saudi Arabia, on Saturday with foreign ministers from Gulf States, referring to the closure of the Dubai office of the National Democratic Institute (NDI).
Clinton said she had discussed the issue with Sheikh Abdullah bin Zayed Al Nahayan, the UAE's foreign minister.
"We are as you know, as anyone who has visited the United States, strong believers in a vibrant civil society ... I expect our discussions on this issue to continue," Clinton told reporters.
The closure of the NDI's office in Dubai came in the same week that a German pro-democracy think tank, the Konrad Adenauer Foundation, was ordered to close in Abu Dhabi.
It said it had received "no understandable explanation" for the move, and it was the second time in three months that the foundation saw one of its foreign offices shuttered, after it was one of the offices closed in Egypt in late December.
The think tank termed the decision an "alarm bell for democratic development in the Arab world".
A spokesman said Guido Westerwelle, the German foreign minister, had personally pressed Al Nahayan to rethink the decision.
The spokesman, said the UAE's ambassador to Berlin was invited for talks on Friday at the ministry to underline the "positive work of the foundation" and seek a "common solution" to reopen the office.
"It is our goal to find a way together with the United Arab Emirates for this to happen," Peschke told a regular government news conference. "But whether and how this could happen I cannot say at this time."
The US-based NDI is among a number of foreign and domestic civil society groups that have been prosecuted in Egypt over their activities.
In Egypt, the authorities accused campaigners for the non-governmental organisations, including the son of US Transportation Secretary Ray LaHood, of working for groups receiving illegal foreign funding and initially prevented them from leaving Egypt.
The UAE, one of the world's top five oil exporters, has escaped the kind of political upheaval that has reshaped much of the Arab world over the past year.