European Union officials said Monday they were in talks with the United States to beef up trans-Atlantic travel security measures, including the possible expanded use of air marshals on flights to and from the U.S.

The measures are related to a new U.S. visa-waiver law that could also see EU countries being pushed to provide more data on passengers on trans-Atlantic flights — or flights that fly over the U.S. but don't land there. An agreement on information-sharing was part of a deal the 27-nation union and the U.S. signed last July.

Washington argues the added measures are needed to ensure those traveling into the U.S. without visas are not a security risk.

EU spokesman Friso Roscam Abbing told reporters that "quite important elements" of the U.S. legislation still need to be worked out by the U.S. Department of Homeland Security. "We are in constant consultation and negotiation with the United States on all of these issues," Roscam Abbing said. "We are still waiting to see what it is exactly the United States is going to propose."

The new visa waiver rules passed by the U.S. Congress last August demanded the U.S. government weigh the participation of European countries in anti-terror measures, including air marshal programs, in deciding whether to drop visa requirements.

Under existing rules, EU governments are each allowed to decide if their national airlines can have armed marshals on board.

U.S. officials have been traveling to several EU nations seeking changes as part of the new law.

The current U.S. visa-waiver program allows citizens from most Western European countries and some other parts of the world to enter the United States without visas, but excludes several of the newer EU members. Some of those — such as Poland, Hungary and the Czech Republic — are U.S. allies with troops in Iraq or Afghanistan.

The U.S. visa waiver program was created in 1988 and was originally focused on preventing illegal immigration into the country.

But since the terrorist attacks of Sept. 11, 2001, the focus has shifted to security, and the program has been altered several times in hopes of strengthening the government's ability to detect and deter terrorists.

The consultations come as the EU considers setting up stricter border checks.

Franco Frattini, the EU's justice and home affairs commissioner is expected to present plans this Wednesday to replicate U.S. security measures at EU borders, including plans to fingerprint all visitors and electronically record each entry and exit.

Critics fear the measures go too far and will do little to weed out terrorists.

"We haven't seen any facts and figures demonstrating the use and need for this," said Dutch EU lawmaker Sophie Int'Veld, a parliamentary expert on the issue.