The US and the UK have said they look forward to working with Egypt's newly elected President Abdel Fattah el-Sisi, while warning the former general to take steps to guarantee freedom of expression.

The White House said it hoped to advance its strategic partnership with Cairo and the "many interests" the countries shares, in a statment published on Wednesday.

A day earlier, British Foreign Secretary William Hague said he looked forward to working with the former army chief's government to strengthen the "broad and productive" relationship between Egypt and the UK.

Both countries urged Sisi, who won Egypt's presidential poll with more than 96 percent of the vote, to ensure freedom of expression was allowed.

"We also share concerns raised by observation groups about the restrictive political environment in which this election took place," the White House statement said.

The statement said observers found the elections were held in accordance with Egyptian law.

Sisi's road to the presidency started with the overthrow of the country's first freely elected president, Mohamed Morsi, last July.

Washington refrained from calling the change of government a coup, an assessment that would have forced it under US law to stop providing Egypt with billions in annual aid.

'Historic day'

Sisi's election has also been welcomed by his main Arab allies, including Saudi Arabia.

Saudi King Abdullah on Tuesday hailed the election of Sisi to the presidency as a "historic day", and called for a donors conference to help Egypt through its economic troubles.

The king said Sisi's sweeping win with 96.9 percent of the vote represents "a new stage for Egypt," in a telegram published by Saudi state news agency SPA.

"To the brothers and friends of Egypt ... I invite all to a donors conference ... to help it overcome its economic crisis," he said, the AFP news agency reported.

Saudi Arabia pledged billions of dollars in aid to Egypt's new authorities after the overthrow of Morsi last July, with Riyadh long seeing Morsi's Muslim Brotherhood as a threat.

After his ousting, it quickly pledged $5bn in aid to Cairo, with Kuwait and the UAE offering a combined $7bn.

King Abdullah also urged "brothers and friends to avoid meddling in Egypt's internal affairs," warning that harming Egypt would amount to "harming Islam, Arabism and Saudi Arabia".

The king appeared to be referring to Qatar, which is accused of supporting the Muslim Brotherhood and whose relations with Saudi Arabia and most other Gulf countries have been strained over recent times. 

He also urged Sisi to open up to the opposition, encouraging him to "accept the other opinion through a national dialogue with all parties whose hands have not been stained by the blood of the innocents," the exception an apparent reference to the Muslim Brotherhood.

Source: Al Jazeera and agencies