As escalating fighting across southwestern Syria continues to displace thousands of people, Jordan has reiterated it will not reopen its borders and instead called on the United Nations to act.

Some 45,000 people are believed to be on the move and headed toward the Syrian-Jordan border, following government airstrikes on a rebel-held area of Syria's Daraa province, according to Sky News.

Jordanian officials said their border, which was sealed in mid-2014, will remain closed.

"We have received enough numbers of Syrian refugees; we already have a large number and we simply cannot receive more," Jumana Ghunaimat, the minister for media affairs, told the Jordan Times. “We are following up closely on the situation in southern Syria, and we are working with the Americans and the Russians to reach a deal to protect our national interest.”

Jordan, the small neighboring country with a population of over 9 million, has 660,000 registered Syrian refugees and estimates that many more live in the kingdom without having registered. Israel has not commented of the wave of displacement, although Syrian residents said many of the displaced have sought refuge near the frontier with the Israeli-occupied Golan Heights.

Jordan's Minister of Foreign Affairs said Tuesday on Twitter the country "is at capacity."

"We’ll keep doing all we can for them. But we can’t host more," he wrote.

When Jordan closed the border in 2014, the action sent around 60,000 people into a camp inaccessible to any medical or humanitarian aid and controlled by exploitative criminal gangs. Jordan's King Abdullah then urged the international community to provide support for the stranded refugees but some were eventually allowed into the country, or at least the heavily restricted conditions of desert refugee camps, according to Sky News.

AIRSTRIKE ON REBEL-HELD NORTHWESTERN SYRIAN VILLAGE KILLS 35

The strategic southern region in Syria borders Jordan and the Israeli-occupied Golan Heights. The Syrian government troops are seeking to dislodge rebels who have been in the area for years, and gain control of the commercial border crossing with Jordan.

The executive director of the U.N. children's agency UNICEF, Henrietta H. Fore, said Wednesday that violence in southern Syria has displaced thousands of children in just three days and killed at least four.

"Horror knows no limit in Syria," she said in a statement. "Those wishing to flee should be allowed to reach safe havens, away from the sights and sounds of war ... The children of Syria have lived through unacceptable suffering. This cannot become the new normal."

On Wednesday, Syrian media said government forces began an operation against the rebels in the southern parts of Daraa, near the Jordanian border.

The Associated Press contributed to this report.