BRUSSELS (Reuters) - The United States wants to increase the number of countries enjoying visa-free entry after opening the door to citizens from six new European Union countries and South Korea, U.S. officials said Friday.

Bolivian passenger waits for fly from Viru Viru airport in Santa Cruz, some 900 km (560 miles) east of La Paz, March 30, 2007. REUTERS/David Mercado

From Monday, travelers from the Czech Republic, Estonia, Hungary, Latvia, Lithuania and Slovakia, as well as South Korea, will be allowed to travel to the United States without a visa provided they fill in a form on the Internet.

Washington is continuing talks with EU countries not yet in the visa waiver program -- Poland, Greece, Bulgaria, Cyprus, Malta and Romania.

“It is our objective to admit additional countries before the change of U.S. administration,” said Jackie Bednarz, a Department of Homeland Security official at the U.S. Mission to the EU.

The visa waiver program includes a further 27 countries, including EU states, Australia, Japan and Singapore.

From January 12, citizens from all countries in the program will be required to register online ahead of traveling to the United States by air or sea.

If the so-called Electronic System Travel Authorization is refused, a traveler will need to apply for a visa. Bednarz said a pilot project showed an approval rate of 99.6 percent.

The new U.S. requirement is the latest in an overhaul of U.S. travel regulations since the September 11, 2001, attacks.

On the online form, the traveler must give his name and travel information, and state whether he has a communicable disease, is a drug abuser, has already been denied a U.S. visa, or “is seeking entry to engage in criminal or immoral activities.”

The online registration at www.cbp.gov/esta is similar to the paper form that travelers from visa-free countries now fill in aboard the plane and hand to border control on arrival in the United States.

A European Commission official said the EU executive was yet to decide whether it considered that the new system was equivalent to reintroducing a visa for European citizens traveling visa-free to the United States.

A U.S. official insisted this was not a visa.

The online form is free but it has not been ruled out that a fee could be applied at some point, the U.S. official said.