The Saudi-led coalition battling Iran-backed insurgents sent more military vehicles and troops across the border into Yemen on Friday in preparation for an offensive to retake the capital, military officials said.
The arrival of reinforcements came as coalition warplanes killed seven rebels in an air raid Friday in eastern Yemen, where Apache helicopters have also joined the fight against the Houthi Shia insurgents.
The strike targeted a military vehicle used by the rebels in the eastern province of Marib, while other air raids struck rebel positions in neighbouring Shabwa province, military sources said.
An AFP reporter at the Wadia border post between Saudi Arabia and Yemen saw at least 40 coalition military vehicles cross over into oil-rich Marib.
The vehicles were carrying Yemeni troops trained in Saudi Arabia as well as coalition troops whose nationality military officials in the area declined to specify.
It came hours after UN special envoy for Yemen, Ismail Ould Cheikh Ahmed, said that the exiled government and the Houthi rebels had agreed to take part in peace talks that "will convene in the region next week".
The UN estimates that more than 4,500 people have been killed in the conflict.
Gulf Arab members of the coalition, in which the UAE is also playing a major role, have reportedly sent thousands of heavily armed reinforcements to Yemen, mainly to Marib, since last week in preparation for the push on the capital Sanaa.
The exiled government has also announced that 10,000 Yemeni fighters are now ready to serve in a "national army being prepared to liberate Sanaa and other provinces".
Military sources in Marib said that the coalition's Apache helicopters were also taking part in the battle against rebels in the province.
"Preparations are ongoing for large-scale military operations to liberate the provinces of Marib and Jawf (in the north) in order to enter Sanaa," which the rebels seized a year ago, one of the Yemeni military officials told AFP.
The pro-government coalition has intensified raids against rebel forces since a deadly missile attack last week killed 60 Gulf troops, most of them Emiratis, in Marib province.
The coalition launched its air war in March after the rebels entered the main southern city of Aden, where President Abedrabbo Mansour Hadi had sought refuge before fleeing to Saudi Arabia.
Since mid-July, pro-Hadi fighters, backed by the coalition, have recaptured Aden and four other southern provinces.