British Foreign Secretary David Miliband has held talks with his Lebanese counterpart Fawzi Salloukh over the future of the Middle East, BBC reported.
Arriving in Beirut, Mr Miliband said it was "time to push for a comprehensive resolution" to the region's troubles.
On Wednesday, he is due to hold talks Lebanese President Michel Suleiman and Prime Minister Fuad Saniora.
Earlier, he met Syrian President Bashar al-Assad in Damascus - the first British politician to do so since 2001.
Speaking afterwards at a joint news conference, Mr Miliband said Syria could play a "constructive role" in bringing stability to the Middle East.
Syrian foreign minister Walid al-Mua'allim said that Iran also had an important contribution to make.
"We believe that good ties with Iran will help the bring security and stability to the region," he said.
Mr Miliband told reporters gathered at Beirut's international airport that the UK was "very committed" to the "vision of a peaceful Middle East".
"Now is the time to push for a comprehensive resolution," he said.
The foreign secretary also announced that Lebanon's president would visit the UK next spring.
Earlier in his tour, Mr Miliband travelled to Israel and the West Bank, holding meetings with Israeli Prime Minister Ehud Olmert and Palestinian President Mahmoud Abbas.