GENEVA, July 23 (Xinhua) -- The United Nations Special Envoy for Yemen, Martin Griffiths, said Tuesday he believes that the war in Yemen, in its fifth year, is "eminently resolvable", but that the Stockholm Agreement is essential for the process to end it.

He addressed a United Nations press briefing here and acknowledged that December's Stockholm Agreement "is taking quite some time for implementation."

Griffith said, "I think it is interesting that both parties continue to insist that they want a political solution. The military solution is not available.

"They remain committed to the Stockholm Agreement and all its different aspects and they see it as the gateway to opening up negotiations on a political solution."

The deal focused on enforcing a cease-fire and a mutual withdrawal of troops from Hodeidah port city as the first phase toward a comprehensive political solution.

Griffith warned also of the "the possibility of Yemen getting dragged into a regional conflict, and much of the time that we have been devoting recently is to try to see how we can make sure that doesn't happen," due to growing regional tensions.

The UN envoy spoke about a recent meeting when negotiators from Yemen's internationally recognized government and Houthi rebels boarded a UN ship in the Red Sea to resume talks on the troop withdrawal from Hodeidah.

He said the two sides "discussed together some crucial issues and made more progress than I would have imagined."

Griffith also said, "The fragmentation of Yemen is an alarming trend, an alarming pattern, which is one of the reasons...why I've always urged speed towards finding a political solution."

The Houthi rebels have recently stepped up missile and drone attacks on Saudi Arabia.

The Yemeni government forces, backed by the Saudi-led coalition, have been locked in clashes with the Iran-allied Houthi rebels in the north, east and west parts of Taiz since April 2015.

Yemen has been mired into a civil war since late 2014 when Shiite Houthi rebels overran much of the country and seized all northern provinces, including the capital Sanaa.

The civil war has killed more than 10,000 people, mostly civilians, displaced 3 million others, and pushed Yemen to the brink of famine.