A day after moving to nullify the Bush administration's new rules restricting family travel to Cuba (search), the House on Wednesday voted to remove barriers to agriculture sales and student exchanges in the island nation.

But, as in past years, actions by both the House and Senate to ease decades of economic and social sanctions imposed on Cuba are expected to make little headway against an administration determined not to make life easier for the Fidel Castro (search) government.

The White House has threatened to veto a $90 billion Transportation and Treasury Department spending bill if it contains any language to weaken sanctions. The bill, for fiscal 2005 programs, passed 397-12.

The House also courted a presidential veto by eliminating a two-year certification exemption for foreign-built trucks that travel in the United States. The provision is aimed at Mexican trucks that, under the 1993 North American Free Trade Agreement (search), were promised full access to U.S. roadways.

Rep. Ernest Istook (search), R-Okla, chairman of the subcommittee overseeing the spending bill, suggested that the Cuba provisions will "evaporate" when the House and Senate come together to write a final version of the bill. The White House is "very unequivocal" about the veto threat, he said, and "my responsibility ... is to produce a bill that will pass into law."

For years, during both the Clinton and Bush administrations, Democrats and free-trade Republicans have, with little success, questioned the effectiveness of trying to end the 45-year-old Castro regime through a policy of isolation.

The Senate Appropriations Committee, on three different spending bills this year, has moved to prevent the government from enforcing restrictions on travel, gift parcels to Cuban family members, and food sales to Cuba.

The House on Wednesday approved two of the Cuba amendments without a roll call vote.

The first, introduced by Rep. Maxine Waters (search), D-Calif., would make it easier to sell agricultural products, medicine and medical supplies to Cuba. Sales of such goods have been legal since 2001 but restrictions on commercial financing and credit guarantees have discouraged exports.

The second, sponsored by Rep. Barbara Lee (search), D-Calif., prohibits funds to enforce regulations promulgated June 30 this year that erect obstacles to American student programs in Cuba. The rules are "just plain undemocratic and punitive and simply don't make sense for Americans," she said.

On Tuesday the House voted 225-174 to approve an amendment by Rep. Jim Davis, D-Fla., that blocks another June 30 rule allowing Cuban-Americans to visit family in Cuba only once every three years. Davis' provision would restore the old system allowing one visit a year.

A far broader proposal by Rep. Charles Rangel, D-N.Y., to end the economic embargo with Cuba, lost 225-188.

Cuban-American Rep. Lincoln Diaz-Balart, R-Fla., led the opposition to any easing of sanctions, saying it was "in bad taste" to give breaks to Castro at a time he is stepping up the suppression of dissidents. "We don't think it is appropriate now to reward the dictatorship with financing," he said of the Waters amendment.

The trucking amendment, backed by Rep. John Olver, D-Mass., prevents the Federal Motor Carrier Safety Administration (search) from enforcing proposed rules to give a two-year exemption from U.S. safety standards for foreign-built trucks that have previously entered the United States. It passed 339-70, but, like the Cuba provisions, may not survive a House-Senate conference.

The Supreme Court in June agreed that the Bush administration had the authority to lift a moratorium on Mexican truckers operating in the United States, a defeat for union, consumer and environmental groups that have sought to ban Mexican trucks from U.S. roads.

Olver stressed that all trucks, whether American or foreign, should meet the same safety standards.

Rep. Jim Kolbe, who opposed the amendment, said Mexican trucks do have to meet the same standards, and the exemption applied only to labeling requirements for the condition of the truck when it was manufactured. "This is a bogus amendment designed to keep Mexican trucks out of the United States," he said.