The Saudi-led coalition fighting the Iran-aligned Houthis in Yemen said on Wednesday its troops were redeploying in line with its strategy to support Yemeni forces, but were not withdrawing.

Yemeni security sources told Reuters the Saudi military had withdrawn from a major military base in Burayqah district in the southern port city of Aden, removing troops, hardware and heavy artillery.

Some of the troops and equipment were loaded in warships in Aden port, while others flew out from the city's airport, the sources said. Long convoys of the kingdom's military were seen on Tuesday heading from Burayqah military base to Aden port, witnesses said.

The spokesman of the Saudi-led coalition, General Turki al-Malki, told Reuters reports circulating about a Saudi military withdrawal from south Yemen were "baseless and unfounded".

"Movement and redeployment of troops based on operational and tactical assessment" was a standard operation "in all military forces across the world", General Malki said.

The new drawdown of Saudi forces followed intense diplomacy from the United States and the United Nations to end a seven-year-old conflict that has killed tens of thousands and put millions at risk of starvation.

U.S. Envoy to Yemen Timothy Lenderking visited Riyadh this week as Washington pressed Saudi Arabia to lift a blockade on Houthi-held ports, a condition from the Iran-aligned group to start ceasefire talks.

However Riyadh first wants U.S. weapons to help the kingdom strengthen its defence systems following Houthi attacks on its territory with drones and ballistic missiles.