The United Nations (UN) has welcomed the agreement between the United States and Russia for a cease-fire in southwest Syria, saying it would enable upcoming peace talks.

The UN's deputy special envoy to Syria Ramzy Ramzy said Saturday the agreement announced a day earlier in Hamburg, Germany is a step in the right direction. He says he hopes other areas in Syria will see similar agreements to reduce violence.

Ramzy is in Damascus ahead of a new round of UN-sponsored peace talks in Geneva on Monday.

The cease-fire goes into effect Sunday at noon Damascus time, according to US officials and the Jordanian government, which is also involved in the deal. The deal marks a new level of cooperation between the US and Russia.

The truce will also help allay growing concerns by neighboring Jordan and Israel about Iranian military ambitions in the area, including fears that Tehran plans to set up a disruptive long-term presence there.

Such apprehensions were stoked by recent movements of militias loyal to Iran and fighting alongside Syrian government forces toward Jordan's border with Syria, and to another strategic area in the southeast, close to where the two countries meet Iraq.

The advances are part of Syrian President Bashar Assad's push to regain territory from rebel groups, some backed by the West, in the southern Daraa province, and from Islamic State extremists in the southeast, near the triangle with Iraq.

But Syria's neighbors suspect that Iran is pursuing a broader agenda, including carving out a land route through Syria that would create a territorial continuum from Iran and Iraq to Lebanon.

Israel has repeatedly said it will not allow Iran to set up a permanent presence in Syria. Israel has carried out a number of airstrikes in Syria against suspected shipments of “game-changing” weapons bound for Hezbollah.

“The question and concern is of course if it will be exploited by the Syrian regime, Hezbollah and Iran to create new facts on the ground,” said Chagai Tzuriel, the director general of Israel's Intelligence Ministry.

The cease-fire for southern Syria is meant to keep all forces pinned to their current positions, said Jordan's government which participated in the talks.

The truce is to be monitored through satellite and drone images as well as observers on the ground, a senior Jordanian official said Saturday, speaking on condition of anonymity because he was not authorized to discuss details with reporters.

Syria ally Russia is to deploy military police in the area.

Information on truce compliance could be shared and discussed in different locations, including Jordan, the official said. Israel did not participate in the truce talks, but was presumably briefed by the US, the Jordanian official said.

Israel is expected to watch for truce violations.

Ahead of Friday's truce announcement, Jordanian and Israeli officials expressed concerns about Iranian ambitions.

The Jordanian official said the international community, regional powers and Jordan would not tolerate the creation of a “land line all the way from Tehran to Beirut.”

Such a movement would disrupt the regional balance and be considered a “super red line,” he said, referring to rival Muslim political camps led by Saudi Arabia and Iran, respectively.

Conflicts between the camps have escalated in recent years, including in proxy wars in Syria and Yemen. Jordan is a US ally and maintains discrete security ties with Israel.

The truce deal, the first such agreement between the Trump administration and Russia, could help the US retain more of a say over who fills the power vacuum left behind as Islamic State is routed from additional territory in Syria.

Washington has been resistant to letting Iranian forces and their proxies gain strength in Syria's south. In recent weeks, US forces have shot down a Syrian aircraft that got too close to American forces as well as Iranian-made drones.

The British ambassador to Jordan, Edward Oakden, said Russia has an important role to play.

Cease-fires have repeatedly collapsed in Syria's six-year-old civil war, and it's not clear if this one will last. The southern Syria truce is separate from so far unsuccessful efforts by Russia, Turkey and Iran to set up “de-escalation zones” in Syria, including in the south.