Libyan rebels say they are being hampered by land mines as they continue their push on Tuesday to gain full control of the eastern oil port of Brega.

More than 40 people on both sides have been killed since last week, when the rebels launched an offensive near Brega against forces loyal to Libyan leader Moammar Gadhafi.

The rebels control much of eastern Libya and parts of the west. They have been fighting since February to end Mr. Gadhafi's four decades of autocratic rule.

NATO warplanes have been helping the rebels by bombing pro-Gadhafi forces under a U.N. mandate to prevent government attacks on civilians.

Meanwhile, U.S. and Libyan officials have presented different interpretations of the direct talks held between the two sides on Saturday.

Washington says the sole objective of the “one-time” meeting in Tunisia was to deliver a “clear and firm” message that Mr. Gadhafi must leave power. However, a Libyan government spokesman described the talks as “a first step in dialogue.”

The meeting took place a day after the United States and more than 30 other nations announced their formal recognition of the opposition Transitional National Council as Libya's legitimate interim government.

In a separate development, an international relief agency says medical workers are struggling to handle a flood of casualties in a western mountainous region where Libyan rebels have gained control of several towns.

The International Committee of the Red Cross says medical facilities in the Nafusa region have been cut off from Libya's health ministry.