Swift relief response, including offering financial aid and equipment support, is of paramount importance to the rescue efforts in earthquake-hit Haiti, two scientists in the United States said Wednesday.

"Time is the most important factor in earthquake rescue," Zhigang Peng, an assistant professor at the School of Earth and Atmospheric Sciences of Georgia Institute of Technology, said in an interview with Xinhua.

Peng referred to the "Golden 72 hours," the most precious time in saving lives after natural disasters such as earthquakes strike.

Victor Tsai, a geophysicist at the United States Geological Survey, told Xinhua that a quick dispatch of aid, including needed machinery, was perhaps the most important thing to do in earthquake relief efforts.

"Of course Haiti is extremely poor, so financial aid from other sources and countries will be necessary if rescue efforts are to succeed," Tsai said.

A magnitude-7.3 quake rocked the Caribbean country of Haiti on Tuesday, crushing thousands of buildings, including the presidential palace and the UN peacekeeping headquarters, and trapping an untold number of people in the rubble in the capital city Port-au-Prince.

On the cause of the earthquake, the two experts said the Caribbean islands lie on a plate boundary between the Caribbean plate and the North American plate, a seismically active region where earthquakes are prone to occur.

"Tuesday's earthquake helped relieve some of the stress that was building up on that plate boundary, and is an expected consequence of the motion known to occur there," Tsai said.

On the many aftershocks following the earthquake, Peng said that "a magnitude-7 earthquake is expected to produce many aftershocks that could last for months to years. Some of them could be large enough to cause additional damage."

Though seismologists still can not accurately predict the time of large earthquakes, casualties and losses can be drastically reduced by improving building standards, the experts said.

"There is a saying in seismology that 'Earthquakes don't kill people, buildings do,'" Tsai said, adding that humans can play a big role in remedying the situation even though they can not predict or get rid of earthquakes.

Better building quality requires the collaboration between scientists, engineers and policymakers, Peng said, adding that Port-au-Prince had been destroyed several times in the past few hundred years by earthquakes and other natural disasters.

"Hence it is very important to ensure quality of the building, especially at cities that are close to major active faults," he added.