BEIRUT - Turkey said Tuesday it is pressing for ground operations in Syria, hoping for the involvement of the U.S. and other allies as a force dominated by Kurdish fighters pushed through rebel lines and captured more territory near the Turkish border.

In Damascus, the UN envoy to Syria suggested that humanitarian aid would be allowed into several besieged areas Wednesday, calling it the "duty of the government of Syria."

"Tomorrow we test this," Staffan de Mistura said after meeting with Syria's foreign minister. The UN later announced the government of President Bashar Assad has approved access to seven such areas across the country and that convoys would head out in the coming days.

De Mistura has been trying to secure aid deliveries to improve the chances of restarting peace talks before the end of February. But those efforts have been clouded by the intense fighting north of Aleppo, where various forces backed by regional and international rivals are clashing over a crucial strip of land linking Syria's largest city to the border with Turkey.

Syrian government troops and allied militias, backed by heavy Russian bombardment, are closing in on the area, hoping to seal off parts of Aleppo held by rebels since 2012 in what would be a major blow to the opposition. Syria's state news agency SANA and opposition activists said government forces have seized two more villages.

U.S.-backed Kurdish forces, which had mainly battled the Islamic State group and remained largely neutral in the civil war, are advancing in the same region, fighting rebels and other insurgents opposed to Assad in a bid to expand a nearby enclave.

A Turkish official told reporters in Istanbul that his country is pushing for ground operations in Syria, hoping for the involvement of the U.S. and other allies against IS.

"Without ground operations, it is impossible to stop the fighting in Syria," the official said, adding that Turkey has pressed the issue in recent discussions with the U.S. and other Western nations.

But he ruled out the possibility of Turkey undertaking unilateral action or the prospect of a joint Saudi-Turkish venture without broader consensus in the U.S.-led coalition against IS. The official spoke on condition of anonymity because he wasn't authorized to speak publicly on the issue.

In Lebanon, the leader of Hezbollah said Turkey and Saudi Arabia are using the fight against IS as a "pretext" to launch a ground operation in Syria.

Both countries are ready to start a regional and international war because of defeats suffered by rebels they support, said Sayyed Hassan Nasrallah, addressing supporters in Beirut via satellite link from his hideout elsewhere in the city. Hezbollah's fighters are in Syria, supporting Assad's forces.

The main Kurdish militia, known as the YPG, dominates the group known as the Syrian Democratic Forces, which also includes Arab fighters. The latest advances by the SDF have alarmed Ankara, which views Syria's Kurds with suspicion. Turkey is also a leading backer of militants trying to overthrow Assad.

SDF official Ahmad Hiso said Turkish troops shelled northern Syria. Since the shelling began three days ago, six civilians have been killed, including a woman and a child, he added.

The Kurdish forces have continued to advance, however, and the SDF captured the village of Sheikh Issa, cutting lines between the rebel stronghold of Marea and other parts of Aleppo province.

The SDF have also captured the major town of Tel Rifaat, formerly one of the largest militant strongholds in the province, as well as the village of Kfar Naseh to the south.

SDF official Ahmad al-Omar said dignitaries from northern Syria are mediating a deal to open a corridor for militants to leave Marea for the northern town of Azaz near the border. The move would lead to SDF forces entering Marea without fighting in what would save the town from wide destruction by Russian warplanes.

Once in Marea, SDF forces would face off against IS. The SDF has been one of the most effective forces in fighting the extremists and has liberated large parts of northern Syria.

Turkey, a NATO member and part of the U.S.-directed coalition conducting airstrikes against IS, views the Kurdish fighters as an extension of the Kurdistan Workers' Party, or PKK, which has waged a decades-long insurgency against Ankara and is considered a terrorist group by the U.S. and other Western nations.

Russia, meanwhile, denied accusations it carried out airstrikes on a Syrian hospital supported by Doctors Without Borders that killed at least 11 people Monday.

The Britain-based Syrian Observatory for Human Rights and other opposition activist groups had said Russian warplanes targeted the hospital in Idlib province.

In a conference call with journalists, Dmitry Peskov, spokesman for President Vladimir Putin, said those making the allegations should rely on the "primary source" - official announcements from the Syrian government.

Syria's UN ambassador told reporters his government has "credible information" that the U.S.-led alliance struck the hospital. Pentagon press secretary Peter Cook said it was not a U.S. attack.

The Syrian ambassador, Bashar Ja'afari, also accused Doctors Without Borders of being a branch of French intelligence. The hospital was installed without prior consultation with the government, and the aid group must "assume the full consequences of their act because ... they did not operate with the Syrian government permission," he said.

The U.S., Russia and other world powers agreed Feb. 12 in Munich to bring about a pause in hostilities that would allow for the delivery of humanitarian aid and the revival of peace talks. The projected truce was to begin at the end of this week but is still very much in doubt.


Associated Press writer Lynn Berry in Moscow, Albert Aji in Damascus, Dominique Soguel in Istanbul, Edith M. Lederer at the United Nations and Zeina Karam in Beirut contributed to this report.