CAIRO (AFP) — Egypt is facing a “critical moment” in its transition to democracy, US Secretary of State John Kerry said on Sunday as he arrived in Cairo on a surprise trip.

“Obviously this is a critical moment of transition in Egypt, enormous challenges,” Kerry said as he met new Foreign Minister Sameh Shoukri. He was also due to meet President Abdel Fattah el-Sissi and vowed “the US is very interested in working closely” with the new government “in order to make this transition as rapidly and smoothly as possible.”

US Secretary of State John Kerry arrived in Egypt Sunday on a surprise trip to push for democracy in the politically tumultuous country as Washington quietly released $572 million in aid.

Kerry, the highest-ranking US official to visit since el-Sissi came to power, was to press the former army chief during his lightning trip to instal greater political freedoms and discuss security challenges.

Since Islamist former president Mohamed Morsi was toppled by el-Sissi in July 2013, a government crackdown on his supporters has left more than 1,400 people dead in street clashes and at least 15,000 jailed.

US officials warned Washington still has deep concerns about the government’s “polarizing tactics,” even though there was a “recognition that Egypt has been going through a very difficult transition.”

Kerry’s visit comes a day after an Egyptian court confirmed death sentences for 183 Islamists, including Muslim Brotherhood chief Mohamed Badie, after a speedy mass trial that sparked an international outcry.

“The Secretary will discuss a variety of issues covering our bilateral relationship as well as regional issues, including Iraq, Syria, Libya, Israeli-Palestinian relations and the extremist and terror threats we all face,” said State Department spokesperson Jen Psaki.

Kerry’s latest diplomatic mission, that will also see him visit Amman, Brussels and Paris, is expected to focus on uniting Iraq’s fractious leaders and repelling insurgents whose lightning offensive has displaced hundreds of thousands, alarmed the world and put Prime Minister Nuri al-Maliki under growing pressure.

The US officials also revealed that a tranche of about $572 million (420 million euros) in aid, which had been frozen since October, was released to the Cairo government about 10 days ago after finally winning a green light from Congress. It will mainly go to pay existing defense contracts.

US officials announced in April they planned to resume some of the annual $1.5 billion in mostly military aid to Cairo, including 10 Apache helicopter gunships for counterterrorism efforts in the Sinai Peninsula.

But the aircraft remain in storage in the US, an official confirmed Sunday.

El-Sissi won some 97 percent of the vote in May elections nearly a year after the toppling of Morsi, and installed an interim government.

Last week, a new Egyptian cabinet led by Prime Minister Ibrahim Mahlab was sworn in with most ministers from the previous interim government still in place.

‘Longstanding relationship’

Soon after arriving, Kerry went into a meeting with the new foreign minister, Sameh Shoukri, a former ambassador to Washington, in a trip which will last only a few hours before he heads to Amman.

“There’s a strong desire on the part of the United States for this transition to succeed,” a senior State Department official told reporters traveling with Kerry.

“We have a longstanding relationship… that’s built on several different pillars. It’s at a difficult juncture right now, that’s true, and we have serious concerns about the political environment,” the official said.

Egypt, one of only two Arab nations to have a peace treaty with Israel, has long been seen as a key strategic ally and a cornerstone to regional stability.

But the political turmoil since the 2011 uprising that toppled strongman Hosni Mubarak has paralyzed Egypt, leaving it more concerned with domestic problems than regional matters despite the upheavals of the Arab Spring.

Washington’s concerns about Cairo include a new law controlling demonstrations, “the lack of space for dissent, mass trials and death sentences,” the official said.

“We are concerned that some of the tactics they’re using to address their security issues are polarizing… they in some ways radicalism certain aspects of Egyptian society in ways that are not supportive of overall stability.”

In a sign of Washington’s unease over the path being taken by Egyptian leaders, no top US cabinet members attended el-Sissi’s inauguration earlier this month.

Kerry will insist in his meetings that the United States still needs to see a return to the rule of law if US-Egypt ties are to improve.

“Because it’s a complicated relationship and we are balancing different interests… we felt like this was an appropriate time… for the secretary to come here to explore those shared interests,” the US official said.