WASHINGTON (CNN) — The White House has criticized House Speaker Nancy Pelosi’s plans to stop in Syria next week during a Middle East trip that began Friday.

She will be the highest-ranking U.S. official to visit Syria since relations deteriorated between Damascus and Washington. 

The United States has accused Syria of aiding the Sunni insurgency in western Iraq with weapons and fighters. Syria also is accused of supporting the militant extremist groups Hezbollah, a Shiite political party and militia, and Hamas.

“We do not encourage and, in fact, we discourage members of Congress to make such visits to Syria,” said White House deputy spokeswoman Dana Perino. “This is a country that is a state sponsor of terror, one that is trying to disrupt the (Prime Minister Fouad) Siniora government in Lebanon and one that is allowing foreign fighters to flow through its borders to Iraq.

“I don’t know what she is trying to accomplish, and I don’t know if anyone in the administration has spoken to her about it,” Perino said. “In general, we do discourage such trips.”

Responding to a follow-up question, Perino added, “We think that someone should take a step back and think about the message that it sends … to our allies.”

Pelosi is scheduled to meet with Syrian President Bashar al-Assad next weekend while in Damascus, according to Imad Moustapha, Syria’s ambassador to the United States. She will be the highest-ranking American to meet with a Syrian president since then-President Clinton met with the late Syrian President Hafez al-Assad in 1994.

Pelosi is expected to address Israel’s Knesset on Sunday. Further details of the trip — her second to the region as speaker of the House — were withheld for security reasons, her office said.

A statement from Pelosi’s spokesman, Brendan Daly, said: “As recommended by the Iraq Study Group, a bipartisan delegation led by Speaker Pelosi intends to discuss a wide range of security issues affecting the United States and the Middle East with representatives of governments in the region, including Syria.”

State Department spokesman Sean McCormack said the administration has advised members of Congress that “it’s not the right time to have those high-profile visitors to Syria.”

However, McCormack said the State Department provided Pelosi with a briefing, and that the U.S. Embassy in Damascus has said it would help if needed.

Late last year, Democratic U.S. Sens. John Kerry and Christopher Dodd, both senior members of the Senate Foreign Relations Committee, met with Syrian President Bashar Al-Assad and challenged his government to play a more constructive role in the region.

BEIRUT, Lebanon, March 30 — Secretary General Ban Ki-moon called Friday for the fulfillment of the United Nations Security Council resolution in August ending the war between Hezbollah and Israel and proposing steps to rid Lebanon of illegal arms and secure its borders.

In a joint news conference with Lebanon’s prime minister, Fouad Siniora, he said Lebanon’s capacity to stop arms smuggling into the country had to be strengthened.

Mr. Ban, on the seventh day of a Middle East tour, said he had heard from Ehud Olmert, the Israeli prime minister, in Jerusalem on Monday that Hezbollah was rearming with matériel brought across the Syrian border.

In reply, Mr. Siniora said there had not been a single incident of smuggling uncovered since the end of the war in August. But he agreed that border control needed improvement.

Asked if the Lebanese Army, in keeping with the Security Council’s demands, was disarming Hezbollah, Mr. Siniora replied that Lebanon would bring about that result through dialogue. “We do not use the word disarm,” he said. “It is not in our dictionary.”

On Saturday, Mr. Ban is expected to tour southern Lebanon, visiting the headquarters and outposts of a 3,000-member United Nations force that has been patrolling a weapon-free zone alongside the Lebanese Army.

Saying he had met in Jerusalem with the families of two soldiers captured by Hezbollah in July, Mr. Ban said he was disappointed that they had not been released and that their captors would not even confirm if they were alive.

Lebanese politics were fractured last November when six pro-Hezbollah ministers resigned from the cabinet, setting off a crisis that still threatens the Siniora government. As Mr. Ban’s convoy swung into the grounds of the hillside presidential compound, chants could be heard from demonstrators who had been camped there since December. They have pledged to maintain their protest until Mr. Siniora resigns.

At the news conference, Mr. Ban said, “One of my main messages here, to all Lebanese leaders I meet with, is that the path of dialogue and compromise has to be the way forward out of this impasse.”

Mohammed Fneish, a pro-Hezbollah legislator, said he told Mr. Ban in a meeting that there had not been any Hezbollah violations of the border with Israel, while the Israelis had crossed the border by air, sea and land more than 1,000 times. Mr. Ban told Mr. Siniora earlier that he had complained to Mr. Olmert in Jerusalem about the high number of Israeli flights over the border reported by the United Nations command in southern Lebanon.

Questioned about why Hezbollah would not give a “sign of life” indication that the families of the captured soldiers were seeking, Mr. Fneish said that would be a matter for negotiation.

Mr. Ban urged rival Lebanese leaders to settle their differences and approve an international court to try suspects in the assassination of former Prime Minister Rafik Hariri in 2005.

Mr. Ban had begun his day by meeting Serge Brammertz, the Belgian prosecutor who is leading the United Nations investigation into Mr. Hariri’s death and other assassinations of Lebanese public figures. He also saw Mr. Hariri’s son, Saad Hariri, who leads the majority in Parliament.

Mr. Siniora said that on Friday, he sent a text of the statute creating the special court to Parliament, which must approve it for it to proceed. It was not received there, though, because the speaker, Nabih Berri, who opposes the tribunal, shut down Parliament for the day.