The number two diplomat in the U.S. State Department met with a leader of Egypt's Muslim Brotherhood Wednesday but was unable to see representatives from the more hard-line Al-Nur party.

State Department spokeswoman Victoria Nuland said Deputy Secretary of State William Burns met with Mohammed Mursi as part of a series of meetings with Egyptian political figures in Cairo. Nuland said it was not a matter of excluding Al-Nur, but that Burns was not able to meet with all of the parties.

She said the meeting was a chance to reinforce U.S. expectations that Egypt's parties will support human rights, women's rights, religious tolerance and the country's existing international obligations.

The meeting, at the headquarters of the Brotherhood's Freedom and Justice Party, came as Egyptians cast ballots in run-offs of round three in the country's staggered parliamentary elections — their first democratic vote since the ouster of president Hosni Mubarak last February.

Elections for parliament's less powerful upper house will begin in late January and finish in March, after which the assembly will write a new constitution.

The Muslim Brotherhood, Egypt's largest and best organized political group, and the ultra-conservative Islamic Salafis, have dominated the first two round of the vote, gaining about 70 percent of the vote.