United Nations Secretary-General Ban Ki-moon warned on Tuesday that a rush of military action against Syria should be restrained as the UN investigation into Syria's alleged use of chemical weapons continues.

The samples taken from the site of an alleged Aug. 21 chemical weapons attack in the Damascus suburbs will be in designated laboratories by Wednesday, and UN inspectors will do their best to speed up the analysis process, Ban said before heading for St. Petersburg, Russia, for a summit of Group of 20 (G20) slated for Thursday and Friday.

"I am pleased to announce that all bio-medical and environmental samples will have arrived at designated laboratories by tomorrow (Wednesday)," he told a press conference.

"We are doing our utmost to expedite the process," he said, stressing the importance of not jeopardizing the scientific timelines required for accurate analysis.

Ban said the sample analysis will be conducted in an objective and impartial manner and strictly in line with internationally recognized standards.

He also said he has already briefed the 15 members of the Security Council on the status of the investigation, adding that the UN high representative for disarmament affairs, Angela Kane, was to brief other UN member states.

Ban made it clear that the use of the banned weapons cannot be tolerated and appealed for unity among the Security Council member states in developing an appropriate response, should the chemical weapons allegations prove to be true.

"As I have stressed repeatedly, if confirmed, any use of chemical weapons by anyone under any circumstances would be a serious violation of international law and an outrageous war crime, " he said. "Any perpetrators must be brought to justice ... There should be no impunity."

UN inspectors reportedly completed their probe in Syria on Saturday and the US government is launching a lobbying campaign seeking Congressional approval for a strike against Syria.

On Tuesday, US President Barack Obama urged Congress for "a prompt vote" to authorize military action against Syria, and leaders of both parties in the Republican controlled House said they will back Obama.

Meeting with Congressional leaders at the White House, Obama promised his proposed strike against Syria will be "limited" and "proportional."

"This is a limited, proportional step that will send a clear message, not only to the Assad regime, but also to other countries that may be interested in testing some of these international norms, that there are consequences," Obama said. "This is not Iraq and this is not Afghanistan."

House Speaker John Boehner, who spoke to reporters after the meeting, pledged his support, saying the United States had to respond to the use of chemical weapons in Syria, and called for members of Congress to support the president.

The White House on Aug. 31 sent Congress a draft resolution to authorize a military strike against Syria. Obama said the strike would "not involve boots on the ground."

Yet US Secretary of State John Kerry said Tuesday at a Senate hearing that boots on the ground may be needed in Syria if chemical weapons were to fall into wrong hands, a scenario representing a clear danger to the United States and its allies.

In the event of a "cache" of chemical weapons needing to be secured, Kerry said the need for boots on the ground may arise, but he later assured lawmakers that President Barack Obama has no intention of sending troops to fight Syria's civil war.

"There will not be American boots on the ground with respect to the civil war," said Kerry, in response to Senator Bob Corker's question.

"President Obama is not asking America to go to war," Kerry said. "He is asking for authorization to degrade and deter Bashar al-Assad's capacity to use chemical weapons."

Although the Obama administration is trying to secure lawmakers' support for a strike on Syria, a recent poll showed the majority of Americans oppose the potential military action.

According to an ABC News-Washington Post poll released Tuesday, 59 percent of Americans are against a missile strike in Syria and only 36 percent of Americans support it.

Russia reported weeks ago that its investigation of an earlier alleged chemical weapons attack in Syria showed that the attack was carried out by opposition forces.

Lebanese President Michel Suleiman expressed Tuesday his rejection of foreign military intervention in Syria, instead wanting to reach a political solution to the unrest in the neighboring country.

Suleiman made his remarks during a meeting with the ambassadors of the permanent members at the UN Security Council, UN Special Coordinator for Lebanon Derek Plumbly and representatives of the European Union and Arab League in Beirut, according to a statement by the presidential media office.