* Progress in aid access doesn't match scale of crisis -UNICEF
* Aid workers says Syria proposes aid link into north-east
* Syrians are now world's biggest displaced population
By Dominic Evans
ZAHLE, Lebanon, March 14 (Reuters) - Syria's government has promised greater access for aid groups supporting millions of Syrians, but faster progress is needed to tackle a dire humanitarian crisis, the head of the United Nations children's agency said on Friday.
UNICEF executive director Anthony Lake, speaking at a refugee camp for Syrians in Lebanon's Bekaa Valley, said he was encouraged by "business-like" talks he held this week with Syrian officials in Damascus and Homs.
"They said yes, they would be offering more access, allowing us to bring in more different kinds of supplies," Lake said, adding that it had already become easier to move food and medicine across frontlines separating President Bashar al-Assad's forces from rebel fighters.
"We have to translate that now into continuing and much more rapid progress because the progress is not equal to the scope of the tragedy," he told Reuters.
In a rare display of unity over Syria, the U.N. Security Council last month called unanimously for greater aid access in Syria, including a demand for cross-border access which Damascus has resisted because it has lost control of some border regions.
Lake gave no details, but aid workers said Syria had offered to let relief goods pass through Turkey's Nusaybin crossing into northeastern Syria, a Kurdish region which has assumed a degree of autonomy but where Assad's security forces are still present.
Perhaps intentionally, the proposal is likely to unsettle Turkey, which would be nervous about opening the border into an area of Syria largely controlled by fighters linked to the Kurdistan Workers Party (PKK) which has waged a three-decade insurgency in Turkey.
The aid workers said United Nations officials based in Turkey were seeking access through at least two other crossings, including the Bab al-Hawa frontier which could open up the rebel-held provinces of Idlib and Aleppo to international aid.
NINE MILLION DISPLACED
As Syria's devastating conflict enters its fourth year, more than 2.5 million Syrians are living as refugees in neighbouring countries and another 6.5 million are displaced internally.
The number of people displaced now exceeds 40 percent of Syria's pre-war population, the highest total in the world, the head of the refugee agency UNHCR said.
"Nine million people are displaced, between refugees and internally displaced - the largest displaced population in the world today," Antonio Guterres told Reuters.
"(That is) something that really should deserve a much stronger commitment from the international community."
In another reflection of the unprecedented scale of Syria's crisis, Guterres said the influx of one million refugees into Lebanon, whose own population is a little over four million, meant it has the largest per capita number of refugees in the world since the UNHCR was set up after World War Two.
"Lebanon has been left essentially alone," he said.
International donors have been unwilling to give money directly to Lebanon because of political turmoil which has blocked the formation of a functioning government for a year.
The World Bank has estimated that the Syrian crisis could cost Lebanon $2.6 billion, but an international meeting in Paris last week committed only a few million dollars to a trust fund for development projects in the country.
"It's high time for the international community to express active solidarity ... with those countries like Lebanon, Jordan, Turkey, Egypt, Iraq that are receiving the Syrians and protecting them in this tragic hour for the Syrian nation," Guterres said.
(Reporting By Dominic Evans; Editing by Alistair Lyon)