British Prime Minister Theresa May | EPA/Facundo Arrizabalaga Theresa May urges Saudi prince to reduce tensions in Gulf May calls for de-escalation of conflict.

British Prime Minister Theresa May on Monday urged the newly appointed heir to the Saudi throne to help reduce tensions with Qatar.

In a statement, a Downing Street spokesperson said May raised the ongoing diplomatic crisis in the Gulf with Prince Mohammed bin Salman of Saudi Arabia during a phone call.

“The prime minister raised the issue of the ongoing isolation of Qatar in the region. She reiterated the need for all sides [to] take urgent steps to de-escalate the situation and restore Gulf Cooperation Council unity," the statement said.

Some of the Arab world's biggest powers — including Saudi Arabia, Bahrain, Egypt, Yemen and the United Arab Emirates — cut ties with Qatar in early June, recalling their ambassadors and preventing goods reaching Qatar through their ports.

They have accused Qatar of destabilizing the region by supporting extremism and terrorism, though a warming of relations between Doha and Iran is also regarded as a factor in the crisis.

Qatar has denied the allegations and said that the demands of the Arabs states — such as closing the Al-Jazeera TV network — violate international law.

Saudi Arabia's king appointed his son Mohammed bin Salman as crown prince in June, making him first in line to the throne.

On Monday, Saudi Arabia and three other Arab states gave Qatar an extra two days to accept a list of demands or face further sanctions, a decision which May praised. May "welcomed the extension of the deadline ... and noted that this demonstrated the willingness of all parties to make progress towards a solution. She said the U.K. remains committed to supporting this process."

Qatari Foreign Minister Sheikh Mohammed bin Abdulrahman Al-Thani delivered Qatar's response to the demands Monday during a trip to Kuwait, which is acting as a mediator in the crisis, though the details of the response were not immediately available.

May's call to reduce tensions is essentially a restatement of her position from mid-June, when she also called for a de-escalation of tensions in the region.

In March, May announced that the United Kingdom and Qatar had established a joint economic and trade committee to pave the way for a post-Brexit trade agreement, part of a larger effort to expand global trade ties.