BEIRUT (AFP, REUTERS, XINHUA) - Close allies and traditional adversaries of Lebanon paid tribute on Tuesday (Aug 4) to the victims of massive and deadly twin blasts in Beirut, as condolences and offers of help poured in.

Lebanese Prime Minister Hassan Diab called on "friendly countries" to support the country already reeling from its worst economic crisis in decades as well as the coronavirus pandemic.

UN chief Antonio Guterres expressed his "deepest condolences... following the horrific explosions in Beirut" which he said had also injured some United Nations personnel.

United States President Donald Trump said "it looks like a terrible attack" and that US generals had told him that the powerful explosions appeared to have been caused by a "bomb of some kind", without offering evidence.

Secretary of State Mike Pompeo tweeted that "we are monitoring and stand ready to assist the people of Lebanon as they recover from this horrible tragedy".

In the region, Gulf nations were among the first to react, with Qatar promising to send field hospitals to support the medical response.

Qatar's ruler Emir Sheikh Tamim bin Hamad Al-Thani wished "a speedy recovery for the injured", while the United Arab Emirates' Vice-President and ruler of Dubai, Sheikh Mohammed bin Rashid Al-Maktoum, tweeted "our condolences to our beloved people in Lebanon".

Kuwait said it would also send emergency medical aid.

Egypt expressed "deep concern" at the destruction, and Arab League chief Ahmed Aboul Gheit offered condolences, stressing "the importance of finding the truth about the explosions".

And in an unusual move, neighbouring Israel offered humanitarian aid - to a country with which it is still technically at war.

"Defence Minister Benny Gantz and Foreign Minister Gabi Ashkenazi, on behalf of the State of Israel, have offered the Lebanese government - via international intermediaries - medical and humanitarian aid, as well as immediate emergency assistance," a statement read.

Iran's president Hassan Rouhani also offered to send medical aid to Lebanon and treat people injured in the blast.

"Iran announces its readiness to send medical aid to Lebanon and also offers treatment of the injured and other necessary medical assistance," Rouhani said, according to state TV.

"We hope that the circumstances of this incident will be determined as soon as possible and that peace will return to Beirut.

'STAY STRONG, LEBANON'

Jordan's Foreign Minister Ayman Safadi said Amman was ready to provide any help Lebanon needed, while Iran said it was "fully prepared to render assistance in any way necessary".

"Our thoughts and prayers are with the great and resilient people of Lebanon," Iranian Foreign Minister Mohammad Javad Zarif tweeted.

"Stay strong, Lebanon."

Outside the region, Indian Prime Minister Narendra Modi on Wednesday expressed shock and sadness at the explosion and offered his thoughts and prayer to the victims.

"Shocked and saddened by the large explosion in Beirut city leading to loss of life and property. Our thoughts and prayers are with the bereaved families and the injured," he said on Twitter.

President Vladimir Putin said that "Russia shares the grief of the Lebanese people", according to a Kremlin statement.

"I ask you to convey words of sympathy and support to the families and friends of the victims, as well as wishes for a speedy recovery to all affected."

Washington said it too would help.

"We extend our deepest condolences to all those affected, and stand ready to offer all possible assistance," a State Department spokesman said.

French Foreign Minister Jean-Yves Le Drian said the country was "ready to provide assistance according to the needs expressed by the Lebanese authorities".

Britain's Prime Minister Boris Johnson called the pictures and videos from Beirut "shocking".

"All of my thoughts and prayers are with those caught up in this terrible incident," he wrote on Twitter.

"The UK is ready to provide support in any way we can, including to those British nationals affected."

British Junior Education Minister Nick Gibb said on Wednesday that it was too early to speculate on the cause of the massive blast, saying: "The Lebanese authorities are of course investigating the cause of that tragedy and before we have the results of that inquiry it is premature to speculate".

He also told Sky News, adding that Britain was discussing what technical and financial assistance could be offered to Lebanon.

Canadian Prime Minister Justin Trudeau wrote on social media to say "we think of all those who were injured in this tragic explosion, as well as those who are trying to find a friend or family member or who have lost a loved one. We're ready to help you."