Syrian Foreign Minister Walid Muallem on Wednesday rejected foreign meddling in his country's internal affairs while stressing Damascus is keen to maintain good ties with longtime ally Turkey.

"We are keen on maintaining good relations with Turkey with which we share a common border of 850 kilometers," Muallem told a press conference in Damascus.

Hamas chief Khaled Meshaal held talks with Turkish officials on efforts to achieve Palestinian unity during a two-day visit to Istanbul ending later Wednesday, diplomats said.

Meshaal's talks in Turkey's largest city coincided with a four-day trip to the capital Ankara by Palestinian leader Mahmoud Abbas, who heads Fatah, at a time when Palestinian officials have reported disagreements between the two groups over the formation of a unity government.

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."

The U.S. government tightened sanctions against three Libya-controlled banks in Turkey, Tunisia and Lebanon on Tuesday, ratcheting up the pressure on leader Moammer Gadhafi's support.

The U.S. Treasury Department said it had targeted three foreign Libyan-owned banks, identified six additional companies subject to sanctions, and lifted sanctions against a former Libyan oil minister who defected from the Gadhafi regime last month.

Palestinian leader Mahmoud Abbas arrived in Ankara Tuesday for talks with Turkish leaders amid disagreements over the formation of a Palestinian unity government, officials said.

Abbas will have a "private program" before talks with Turkish leaders on Thursday and Friday, a Turkish diplomat told Agence France Presse, without giving other details.

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.

Israel and Turkey have been holding secret talks at several levels to end their diplomatic crisis, Haaretz newspaper reported on Tuesday, quoting a senior Israeli official.

The report, for which there was no confirmation, said an official representing Israeli Prime Minister Benjamin Netanyahu and Feridun Sinirlioglu, undersecretary at the Turkish foreign ministry, were involved in the discussions.

Turkish President Abdullah Gul has said that Syrian President Bashar al-Assad should transform the autocratic regime in his country into a multi-party system, following a televised address by the Syrian leader to the nation Monday.

Gul told reporters late on Monday that Assad’s speech was “not enough.”

Israeli Defense Minister Ehud Barak has said that Syrian President Bashar Assad has lost his legitimacy and the fall of his regime would deal a blow to Iran and Hizbullah.

In an interview with French daily Le Figaro over the weekend, Barak said: “If Assad falls, this would deal a severe blow to Iran and Hizbullah, a significant weakening of the Shiite arc.”