The Obama administration has struggled to explain why its ambassador to Syria participated in a sanitized trip to the country's restive north that was sponsored by President Bashar Assad's regime to attempt to justify its military crackdown.

State Department spokeswoman Victoria Nuland said Monday's trip to the abandoned town of Jisr al-Shughour allowed Ambassador Robert Ford to "see for himself the results of the Syrian government's brutality."

U.N. Secretary General Ban Ki-moon urged Syrian President Bashar Assad on Tuesday to make credible reforms "without delay," after the Syrian leader offered a national dialogue to end months of anti-regime protests.

"He urges the president to carry on these reforms without delay and in a way that is both genuine and credible," Ban's spokesman Martin Nesirky said.

Phalange Party leader Amin Gemayel on Tuesday denied that the meetings held recently by the March 14 forces in France were aimed at “drawing up a plan for the future,” noting that “there’s no need to agree on a plan, as coordination with former premier Saad Hariri has not stopped.”

In an interview with France 24 television, Gemayel clarified that the meeting he held in Paris with Hariri was aimed at consulting with the ex-PM on “how to deal with a government controlled by Hizbullah.”

Syrian security forces opened fire on protesters on Tuesday, killing four people, even as President Bashar al-Assad ordered a general amnesty, activists said.

"Two civilians were killed in Homs and six wounded when security forces opened fire on demonstrators calling for freedom," an activist in the central city said.

France stepped up pressure Monday on the United Nations to speak out against Syria's deadly crackdown on protests, but Russia again said it opposed "interference" in the country's internal affairs.

"The U.N. Security Council cannot remain silent for much longer," French Prime Minister Francois Fillon said during a joint press conference in Paris with his Russian counterpart Vladimir Putin.

Lebanon's authorities have released all Syrian refugees in Lebanon who had been detained for not having identity papers, activists said on Tuesday.

"Lebanese authorities have now released all Syrians who fled into Lebanon and were later detained for not having identity papers," human rights lawyer Nabil Halabi, who heads the Lebanese Institute for Democracy and Human Rights, told Agence France Presse.

Gunshots and explosions were heard Tuesday from the Syrian side of Turkey's border with the unrest-hit Arab country, where thousands of fleeing people have massed, an Agence France Presse reporter said.

The shooting appeared to come from a hill overlooking the demarcation line at the frontier, about a kilometer from the Turkish border village of Guvecci, the reporter said.

The International Committee of the Red Cross said Tuesday after talks with Syrian authorities that it has been granted access to areas and people affected by the unrest in the Middle Eastern country.

"The Syrian officials were receptive, and agreed to give the ICRC and the Syrian Arab Red Crescent wider access to areas of unrest," said ICRC president Jakob Kellenberger.

President Bashar Assad on Tuesday ordered a new general amnesty, a day after an offer of "national dialogue" to end Syria's deadly unrest and as a huge crowd rallied in Damascus in his support.

"President Assad has issued a decree granting a general amnesty for crimes committed before the date of June 20, 2011," state news agency SANA announced without giving details.

Tens of thousands of people rallied Tuesday in central Damascus in support of President Bashar Assad, a day after he offered a national dialogue to end Syria's political crisis, an Agence France Presse correspondent said.

Omeyyades Square was turned into a sea of pro-Assad demonstrators, waving Syrian flags and the president's portrait, chanting, "We will sacrifice ourselves for you, Bashar!"