Top US diplomat John Kerry arrives in Saudi Arabia later on Wednesday for talks on Yemen after the UN-brokered dialogue collapsed and as international concerns were mounting over civilian casualties.

Top US diplomat John Kerry arrives in Saudi Arabia later on Wednesday for talks on Yemen after the UN-brokered dialogue collapsed and as international concerns were mounting over civilian casualties.

Over two days, Kerry is to meet Saudi Foreign Minister Adel al-Jubeir and other Gulf ministers.

He will also meet UN Yemen envoy Ismail Ould Cheikh Ahmed and Britain's Under Secretary of State for the Middle East Tobias Ellwood.

The kingdom leads an Arab coalition that has been since March 2015 launching brutal aggression on Yemen in a bid to restore power to fugitive ex-president Abd Rabbu Mansour Hadi who is a close ally to Riyadh.

As the civilian death toll continues to climb, the kingdom has faced mounting criticism from human rights groups.

On Monday, a group that campaigns for stricter arms sales controls said that Western powers were breaking international law by selling vast amounts of weapons to Saudi Arabia that are being used to hit civilians in Yemen.

The Control Arms Coalition said Britain, France and the United States were flouting the 2014 Arms Trade Treaty (ATT), which bans exports of conventional weapons that fuel human rights violations or war crimes.

Medecins Sans Frontieres (MSF) said last week it was evacuating its staff from six hospitals in northern Yemen after a Saudi-led coalition air strike hit one of its hospitals, killing 18 people.

Meanwhile, calls within the US have been pressuring Washington over its military support to Riyadh.

Last week, a US Senator slammed his country's administration over bombing civilians in Yemen.

The Saudis are the ones dropping the bombs, but "there's an American imprint on every civilian life lost in Yemen," Sen. Chris Murphy (D-Conn.) told CNN's Jake Tapper on August 16.