She said that with the new assistance, the United States was providing a total of $220 million to help Syrians.
"Too many people — an unconscionable number of Syrians — are not able to get daily bread, in addition to other supplies," Lindborg told journalists after a visit to a Syrian refugee camp near Turkey's border with Syria.
In a rare gesture, Syria's Interior Ministry called on those who fled the country during the civil war to return, including regime opponents. It said the government will help hundreds of thousands of citizens return whether they left "legally or illegally."
Syrian opposition figures abroad who want to take part in reconciliation talks will also be allowed back, according to a ministry statement carried late Thursday by the state SANA news agency.
If they "have the desire to participate in the national dialogue, they would be allowed to enter Syria," it said.
The proposed talks are part of Assad's initiative to end the conflict that started as peaceful protests in March 2011 but turned into a civil war. Tens of thousands of activists, their family members and opposition supporters remain jailed by the regime, according to international activist groups.
Opposition leaders repeatedly have rejected any talks that include Assad, insisting he must step down. The international community backs that demand, but Assad has clung to power, vowing to crush the armed opposition.
More than 60,000 people have been killed since the conflict began, according to the U.N.
Activists also said two cars packed with explosives blew up near a military intelligence building in the Syrian-controlled part of the Golan Heights, killing eight. Most of the dead were members of the Syrian military, the Observatory said.
The Syrian government had no comment on the attacks, which occurred Thursday night in the town of Quneitra, and nobody claimed responsibility for them.
Car bombs and suicide attacks targeting Syrian troops and government institutions have been the hallmark of Islamic militants fighting in Syria alongside rebels trying to topple Assad.
Quneitra is on the cease-fire line between Syria and Israel, which controls most of the Golan Heights after capturing the strategic territory from Syria in the 1967 war.
Associated Press writers Albert Aji in Damascus, Syria, Suzan Fraser in Ankara, Turkey and Zeina Karam in Beirut contributed to this report.
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