DUSHANBE (AFP) - Tajikistan and Uzbekistan have agreed the transit of non-lethal US supplies for troops in Afghanistan, a US admiral said Friday, as Washington seeks new routes for supplying its operations "Tajikistan has given its agreement to the use of its rail and automobile routes for the transit of non-lethal supplies to Afghanistan," US Rear Admiral Mark Harnitchek was quoted as saying in Dushanbe by Tajik television. He said that Uzbekistan had also "agreed" to the transit and Washington planned to send 50-200 containers weekly from Uzbekistan into Tajikistan and then by land into neighbouring Afghanistan. Washington has been seeking new routes for supplies to Afghanistan after Kyrgyzstan's shock announcement that it is to close a US air base that has served as a key transit point for supplies. Harnitchek, who spoke after a meeting with Tajik Foreign Minister Hamrokhon Zarifi, is the latest top US official to pass through on a region increasing in strategic importance as West steps up Afghan operations. The spokeswoman for the US embassy in Dushanbe, Jackie McKennan, emphasised after his comments that "no formal agreement has been signed" between the sides. "He (Harnitchek) is on a working visit, just reviewing the infrastructure. Nothing formal has been concluded today." The Uzbek foreign ministry in Tashkent declined to comment on whether it had approved the transit across its territory. General David Petraeus, head of Central Command, which oversees the region, travelled to Uzbekistan on Tuesday in a visit widely seen as a sign Washington was seeking to use the country as a transit route for Afghanistan.