The inter-governmental agreement on establishing the Trans-Asian Railway (TAR) network aims to promote trade and balanced development in the world's fastest-growing continent.

The signing came on the first day of a two-day annual ministerial meeting on transport, organised by the UN Economic and Social Commission for Asia and the Pacific (UNESCAP).

"By signing today, you infuse life into the agreement," UNESCAP executive secretary Kim Hak-Su told them.

The 81,000-kilometer (50,200-mile) network, first mooted by the UN back in 1960, is also dubbed the "Iron Silk Road" after the ancient trade route. It would link capitals, ports and industrial hubs across 28 Asian countries all the way to Europe.

UN officials cited procedural matters rather than disagreement over the project as the reason why 10 of the 28 states did not sign. They have another two years to do so.

The railway network will ease international trade and create "the conditions for shared prosperity," Kim told the signatories.

He said earlier in the day the TAR would "link the hinterland areas in the deep interior of the Asian continent with Asia's bustling maritime cities and European markets."

Twelve of the world's 30 landlocked countries are in Asia.

"These linkages will provide seamless connectivity through transport arteries to Asian ports and European markets," Kim said.

UN Secretary General Kofi Annan, in a message to the meeting, said advances in transport "improve productivity, reduce costs and promote trade. That in turn encourages economic growth and social development."

Kim has said he expects the accord to come into force in the second half of next year after eight countries ratify it.

The ratification would encourage international lenders like the Asian Development Bank to seriously consider loan requests from TAR signatories, some of whom are in desperate need of finance, he said.

Wang Zhiguo, China's deputy railways minister, said his country ardently backs the project.

"The Chinese economy continues to grow through efforts to improve and maintain efficient transport and logistic systems," he told the forum.

"We're signing the agreement because we can fulfil many of our goals in transport with it."

Alexander Misharin, Russia's deputy transport minister, said Moscow was working hard to modernise its vast network, including the trans-Siberia railway connecting to Korea, in support of the TAR.

His country was one of the signatories.

Despite the enthusiasm among many countries, the slow progress over the past five decades indicates the challenges still ahead.

The TAR network would connect trans-Asian railway networks with Russia and Mongolia in the north, Malaysia in the south, South Korea in the east and Turkey in the west.

But one stumbling block is North Korea. South Korea would have to traverse its territory to gain access to the Russian or Chinese rail networks.

Work has been completed on laying track across the heavily fortified inter-Korean frontier. But planned test runs were cancelled in May amid tensions over other issues.

Continent-wide problems include switching between different-gauge tracks, where to stop, how to handle sometimes tricky quarantine and immigration paperwork, and how to safely ferry cargo and people across many borders.

But Asia, home to 60 percent of the world's population and generating 26 percent of the world's economic output, deserves better transport, UNESCAP chief Kim has said.

It boasts 13 of the world's top 20 container seaports but has fewer than 100 "dry ports" -- inland container depots. Europe, by contrast, has 200 and the United States 370.