Kofi Annan, the UN chief, led those expressing sadness and said a UN disaster response team was ready to help with humanitarian relief.
"The secretary-general is deeply saddened by the loss of life, the hundreds of injuries and the destruction suffered by the people of Indonesia after the earthquake that struck Yogyakarta on the southern coast of Java," a UN spokesman said.
Britain and France also offered a quick response to the disaster that struck the historic city of Yogyakarta and its surroundings.
"We're geared up to give any help that is required as soon we're asked to, and when we are asked, we will respond very, very quickly," said Hilary Benn, the British secretary of state for international development.
Vladimir Putin, Russia's president, offered his condolences along with the president of China, Hu Jintao, and Giorgio Napolitano, Italy's head of state.
The European Commission said it would release up to three million euros ($3.8 million dollars) in emergency aid in response to the devastating earthquake.
"We are ready to help the victims of this tragedy and recognise how important it is to do it as speedily as possible," said Louis Michel, the EU humanitarian aid commissioner.
The United Nations Children's Fund said it was preparing emergency aid for survivors including 2,000 tents and 9,000 tarpaulins.
Japan said it was sending a relief team and was ready to provide aid.
A team of about seven people including doctors and bureaucrats will head to Indonesia on Sunday to assess the needs, a Japanese foreign ministry official said.
"If the government of Indonesia makes a formal request, we will respond," he said. "The Japanese government is always ready to help."
Malaysia, which neighbours Indonesia, also said it would send a search and rescue team and medical supplies.
Najib Razak, Malaysia's deputy prime minister, said a 56-member team, five doctors and paramedics would leave for the province on board a Royal Malaysian Air Force plane late on Saturday.
The Spanish government also offered immediate assistance through the Spanish agency for international cooperation.