Jordan's Foreign Minister Ayman Safa said via Twitter that while there were now displaced people at the border, the country would nonetheless remain sealed and that it was the responsibility of the United Nations to secure the displaced within Syria's borders.
Government helicopters dropped barrel bombs on the city of Deraa on Monday for the first time in almost a year, a rebel and a war monitor said, extending an assault in southwest Syria.
This photo provided Monday, June 25, 2018, by Nabaa Media, a Syrian opposition media outlet, shows smoke rising over buildings that were hit by Syrian government forces bombardment, in Busra al-Harir, in Daraa, southern Syria.
Government forces opened a new front against the rebel-held part of Deraa city, the provincial capital, on Tuesday, state media reported.
Relief workers said hospitals had been targeted, too.
Almost 50,000 people have been displaced since the Syrian government and its Russian allies escalated an offensive in the southern province of Deraa last week, prompting concerns at the United Nations over where these displaced civilians have to run.
"We haven't seen massive displacement in this scale in Daraa", the main province in the south, Tom told AFP.
For Assad, the latest push means government forces in the heart of Daraa province and those in adjacent Sweida province are now directly connected.
So far, the Syrian Army has not engaged in any offensive activities on any other frontlines with the rebels in the south.
Air strikes also hit the rebel-held town of Nawa for the first time in almost a year, the Observatory said.
The United Nations warned that up to 750,000 people were at risk as a result of the week-old offensive.
Jordan has offered a refuge to more than 1.3 million Syrians fleeing the raging conflict at home, more than 85 per cent of whom live in host communities outside camps. The government's violent response to the protests, and the rise of an armed insurgency, tipped the country into a civil war that has killed 400,000 people and displaced half the population. Israeli officials have since attributed the drone to Syrian regime forces.
"The Kingdom will not receive any new refugees from Syria under any circumstances", Prime Minister Omar Razzaz said Tuesday after a meeting with Lower House Speaker Atef Tarawneh and heads of the chamber's committees. The strategic area was part of a truce deal reached last July between the United States, Russia and Jordan.
Israel usually does not comment on the strikes it is alleged to have carried out in Syria.