Cairo (dpa) - Qatar on Saturday demanded an end to what it called an "illegal blockade" by a Saudi-led bloc locked in a years-long diplomatic row with the tiny Gulf emirate.

The dispute began in June 2017 when Saudi Arabia, the United Arab Emirates (UAE), Bahrain and Egypt severed diplomatic and transport ties with Qatar, accusing it of supporting and funding terrorists, a charge that Doha denied.

Attempts by Kuwait and the United States to resolve the crisis have been unsuccessful.

On Saturday, Qatar accused the Arab quartet of creating the crisis, saying it has adversely affected the region's stability.

The Saudi-led bloc has repeatedly demanded that Doha downgrade ties with Saudi Arabia's regional rival, Iran, but Qatar rejected that, calling the demand an "infringement of its sovereignty."

Qatar "emphasizes that ending the illegal and unfair blockade has become more pressing," the official Qatari news agency QNA said, citing a statement addressed to the United Nations Security Council.

Qatar's ambassador to the UN, Alya Al Thani, said in the statement that Doha is ready for "unconditional, constructive dialogue" to resolve the crisis, according to QNA.

Saudi Arabia and Qatar are members of the Gulf Cooperation Council (GCC), a US-allied grouping that also comprises the UAE, Bahrain, Kuwait and Oman.

In December, Qatari Emir Tamim bin Hamad Al Thani skipped an annual GCC summit in Saudi Arabia, dashing hopes for ending the rift, one of the most serious experienced by the grouping since it was created in 1981.